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Listed clearances cannot. ROPE GASKET. Step 3. Use one hand to help hold door in position 1. Open burner swing door using procedure previously by lifting up on rear burner housing or applying outlined in Paragraph D of this section. Using hex head, tighten well refer to instructions provided with LWCO Kit. Remove the factory installed socket plug Figure 8. Also refer to instructions provided with jumper from harness socket connector and Auxiliary Dual Limit Control Kit. It can also be vented into 1. See Figure 19. 3. Remove the metal knockout in right side of burner cover.To ensure proper operation, the gate must be level across the pivot point and plumb. Refer to vacuum relief valve manufacturer's instructions. Do not use priority zoning for 1. Install wiring and electrically ground boiler in Hydro-Air Systems. accordance with requirements of the authority 7. Check gasket test procedure: around perimeter of ignitor lid for proper a. Before raising the water level above the Model seal. When disturbed as a result of servicing or repair, RCF becomes airborne and, if inhaled, may be hazardous to your health. The most stubborn OFF DEVICES (when installed) deposits may be removed from the probe by using a diluted amount, 3 parts of water to 1 part See Section XIV Appendix for LWCO Installation of phosphoric acid (H Instructions. With this lower level of protection, care must be exercised to eliminate all of the free oxygen in the system. 5. Boiler is now ready to be put into service. C. Inspect burner swing door insulation, and 1. For access to the combustion chamber remove the rope gasket for signs of damage.Should you require assistance in locating a Burnham Distributor in your area, or have questions regarding the availability of Burnham products or repair parts, please contact Burnham Customer Service at (717) 481-8400 or Fax (717) 481-8408. Also provide the name of the part(s) and part number as listed below. s ' t. http://vernalis.ru/upload_files/craftsman-electric-start-lawn-mower-manual.xml

burnham mpo installation manual, burnham mpo-iq installation manual.

Provisions have been made on the MPO supply manifold for a LWCO. Designed as an optimal replacement boiler for millions of homes with existing chimneys, the MPO-IQ has the highest average efficiency in its class. At the heart of the MPO-IQ is an advanced 3-pass cast iron heat exchanger, combined with a well-insulated powder-coated steel jacket. Even the MPO-IQs Control System is best in class. The IQ Control System allows the MPO-IQ to be easily equipped with an optional energy saving control package that can achieve up to a 15-20 reduction in fuel consumption according to most studies. Our Live Chat hours are:If you have problems accessing your account, please contact us at 1-888-757-4774 and we'll help you out. The three pass cast iron heat exchanger extracts maximum BTUs from the combustion process. Natural Draft Boiler Models Include: Add item to cart for lowest price.Manufacturer's warranty still applies.Join our mailing list to receive exclusive offers and coupons. Please check your inbox, and if you can’t find it, check your spam folder to make sure it didn't end up there. Please also check your spam folder. MPO sections are produced in Burnham’s own state-of-the-art foundry in Zanesville, Ohio, and are the primary reason why the MPO is able to attain an ENERGY STAR-certified 87 AFUE. This device also aids in keeping temperatures consistent within the boiler which provides greater operational efficiencies and allow the boiler to operate with virtually any type of hot water system. Installation features include a plug-and-play wiring junction box with easy plug-in control and accessory connections, and a reversible swing-away door with an easy connect power cord for the burner. http://mcaschool.com/files/fckeditor/craftsman-electric-string-trimmer-manual.xml

The MPO includes a Honeywell electronic high-limit aquastat and provisions for optional plug-in accessories, such as a low water cutoff For maintenance and servicing, the MPO comes equipped with reversible stainless steel flueway baffles, rear cleanout access plates, and ample flueway clearance for easy cleaning. To connect the boiler flue connects to this piece, a flexible stainless steel, double wall, insulated pipe is also available in 5, 10, 15, and 20 foot lengths. For added convenience in installations where These tees fit directly to the rear of the boiler and allow for the pipe to be connected vertically. This dramatically reduces the footprint of the boiler installation, by allowing the MPO to be installed close to a wall. Featuring. When seeking information on boiler, provide Boiler Model Number and Serial Number as shown on Rating Label. These Codes and Regulations may differ from this instruction manual. Authorities having jurisdiction should be consulted before installations are made. In all cases, reference should be made to the following Standards: A. B. C. D. Page 3 DANGER DO NOT store or use gasoline or other flammable vapors or liquids in the vicinity of this or any other appliance. WARNING Improper installation, adjustment, alteration, service or maintenance can cause property damage, personal injury or loss of life. Failure to follow all instructions in the proper order can cause personal injury or death. Page 4 WARNING This boiler must be properly vented. The chimney must be inspected for any obstructions and cleaned prior to each heating season. A clean and unobstructed chimney flue is necessary to produce the minimum draft required to safely evacuate noxious fumes that could cause personal injury or loss of life. Evidence of loose debris and or condensate induced stains at the base of the chimney flue, connector or smokepipe joints may be signs of condensing flue gases. http://ninethreefox.com/?q=node/17716

Our responsibility ceases upon delivery of crated boiler to the carrier in good condition. 2. Any claims for damage or shortage in shipment must be filed immediately against the carrier by the consignee. No claims for variances from, or shortage in orders, will be allowed by the manufacturer unless presented within sixty (60) days after receipt of goods. B. Page 9 I. PRE-INSTALLATION (continued) C. PROVIDE COMBUSTION AND VENTILATION AIR. Local and National Codes may apply and should be referenced. WARNING Adequate combustion and ventilation air must be provided to assure proper combustion and to maintain safe ambient air temperatures. Do not install boiler where gasoline or other flammable vapors or liquids, or sources of hydrocarbons (i.e. bleaches, fabric softeners, etc.) are used or stored. 1. Determine volume of space (boiler room). Page 10 I. PRE-INSTALLATION (continued) 6. Louvers and Grilles of Ventilation Ducts a. All outside openings should be screened and louvered. Apply sealant to the 2” NPT injector threads. Insert injector into 2” NPT upper rear tapping on rear section.Slowly allow the weight of boiler to tilt backward until rear legs rest on floor. WARNING 14. If wood blocks were placed under front legs, lift pipe handles; remove the blocks and lower front legs to floor. Remove pipe handles. Page 22 Figure 11: Boiler Removal from Skid III. These four front section bosses are front jacket panel and door mounting bracket attachment points. 2. Open Jacket Carton and locate jacket front panel (has factory attached 1” fiberglass insulation). Locate the Jacket Front Cover from Control Carton. THE EXISTING WATER Design a piping system and install boiler which will prevent oxygen contamination of boiler water and frequent water additions. 1. There are many possible causes of oxygen contamination such as: a. Addition of excessive make-up water as a result of system leaks. b. Absorption through open tanks and fittings. c. https://grovehilloutfitters.com/images/canon-powershot-s50-camera-manual.pdf

Page 27 Figure 13A: Recommended Water Piping for Circulator Zoned Heating Systems IV. Page 28 Figure 13B: Recommended Water Piping for Zone Valve Zoned Heating Systems IV. Page 29 IV. WATER Boiler PIPING (continued) 5. See Figure 14 for suggested near boiler piping of Option Card Controls. WARNING The use of a low water cut-off device, while not required unless radiation level is below the boiler, is highly recommended. If a low water cut-off is required, it must be mounted in the supply piping above the boiler (see Figure 14). Page 30 V. NATURAL DRAFT VENTING (All Boiler Models) A. Chimney Venting 1. Chimney venting is an important part of a safe and efficient oil fired appliance system. Contact your local fire and building officials on specific requirements for restrictions and the installation of fuel oil burning equipment. Page 31 V. Page 32 V. NATURAL DRAFT VENTING (continued) DANGER CAUTION Any signs of condensate seepage at the base of the chimney shall be inspected immediately. The discoloration may be a sign of chimney damage and must be remedied immediately. Table 5: Wall cutout dimensions Boiler Model No. If necessary, the vent pipe may be cut to required length with a hacksaw or cutoff saw. WARNING DO NOT reduce size of air intake pipe. 3. Start at burner and work towards Direct Vent termination air intake. 4. Remove burner cover. Loosen two screws securing outside air duct bracket to burner cover mounting plate. Assemble the vacuum relief valve balance weight onto the gate. Refer to the vacuum relief valve manufacturer’s instructions for details. 13. Mount the assembled vacuum relief valve gate with balance weight into the tee and fasten with a screw and nut in collar tabs. To insure proper operation, the gate must be level across the pivot point and plumb. Refer to the vacuum relief valve manufacturer’s instructions for details. 14. Page 41 VII.

ELECTRICAL DANGER Positively assure all electrical connections are unpowered before attempting installation or service of electrical components or connections of the boiler or building. Lock out all electrical boxes with padlock once power is turned off. WARNING Failure to properly wire electrical connections to the boiler may result in serious physical harm. Electrical power may be from more than one source. Make sure all power is off before attempting any electrical work. Page 42 Figure 28A: Schematic Wiring Diagram VII. Page 43 Figure 28B: Schematic Wiring Diagram, Burner Options VII. Page 44 VII. Page 45 VIII. OIL PIPING A. General 1. Use flexible oil line(s) so the burner swing door can be opened without disconnecting the oil supply piping. 2. A supply line fuel oil filter is recommended as a minimum for all firing rates but a pleated paper fuel oil filter is recommended for the firing rates below 1.0 GPH to prevent nozzle fouling. NOTICE Do not use compression fittings. Oil piping must be absolutely airtight or leaks or loss of prime may result. Bleed line and fuel unit completely. Page 46 VIII. OIL PIPING (continued) C. Two Pipe Oil Lines 1. For two piped systems, where more lift is required, the two-stage fuel unit is recommended. Refer to Figure 30. 2. Follow the oil pump manufacturer’s recommendations on the proper connections for a two pipe system. Some manufacturers require the insertion of a bypass plug. Page 47 IX. SYSTEM START-UP WARNING All boilers equipped with burner swing door have a potential hazard which can cause severe property damage, personal injury or loss of life if ignored. Before opening swing door, turn off service switch to boiler to prevent accidental firing of burner outside the combustion chamber. Be sure to tighten swing door fastener completely when service is completed. This control contains no field-serviceable parts. Do not attempt to take it apart. www.gulfstreamkelowna.com/files/Drivers-Manual-Texas.pdf

Page 51 Important Product Safety Information Refractory Ceramic Fiber Product Warning: The Repair Parts list designates parts that contain refractory ceramic fibers (RCF). RCF has been classified as a possible human carcinogen. The Oil Primary must be reset manually before the burner can be restarted. B. USING BOILER CONTROL The Boiler Control is located under the Jacket Front Cover, to the left of the Option Panel (Refer to Figure 33). Page 54 X. operating (continued) F. Changing the Adjustable Parameters To adjust parameters such as the High Limit Setpoint and High Limit Differential: 1. Using the Boiler Control display, access the adjustment mode by pressing and holding the Up ?, Down ?, and “I” keys simultaneously for three (3) seconds. Select an option. Page 55 X. operating (continued) 7. Priority Time (???) When the Priority Time parameter is set to “on” and Domestic Hot Water (DHW) call for heat is “on” the DHW demand will take “Priority” over home heating demand and the system circulator will be forced “off”. Priority Time ends and the system circulator is released to service home heating demand when Domestic Hot Water call for heat is over. When an external limit contact closes (boiler water is cold) the boiler is started and the ZC and C1 output terminals are de-energized. Page 57 XI. MAINTENANCE AND SERVICE INSTRUCTIONS A. MAINTENANCE OF LOW WATER CUT-OFF DEVICES (when installed) See Instructions provided with Low Water Cut-off Option Card for Installation Instructions. WARNING Probe type low water cut-off devices require annual inspection and maintenance. 1. PROBE TYPE LOW WATER CUT-OFF Although these devices are solid state in their operation, the probe is exposed to possible contamination in the boiler water and subject to fouling. Page 58 XI. MAINTENANCE AND SERVICE INSTRUCTIONS (continued) c. Remove relief valve using extreme care to avoid damaging it. d. Add an appropriate amount of recommended boil out compound. e. Replace relief valve. f. {-Variable.fc_1_url-

Fill the entire system with water. g. Start firing the boiler. h. Circulate the water through the entire system. i. Vent the system, including the radiation.Page 59 XII. BOILER Cleaning WARNING All boiler cleaning must be completed with burner service switch turned off. Boilers equipped with burner swing door have a potential hazard which can cause severe property damage, personal injury or loss of life if ignored. Disconnect the burner plug from the receptacle in the front jacket. Page 60 XII. BOILER Cleaning (continued) Figure 35: Cleaning of Boiler Flueways WARNING The boiler must be connected to an approved chimney in good condition. Serious property damage could result if the boiler is connected to a dirty or inadequate chimney. The interior of the chimney flue must be inspected and cleaned before the start of the heating season and should be inspected periodically throughout the heating season for any obstructions. Page 61 XIII. TROUBLE SHOOTING A. COMBUSTION 1. NOZZLES — Although the nozzle is a relatively inexpensive device, its function is critical to the successful operation of the oil burner. The selection of the nozzle supplied with the MPO-IQ boiler is the result of extensive testing to obtain the best flame shape and efficient combustion. Other brands of the same spray angle and spray pattern may be used but may not perform at the expected level of CO2 and smoke. Page 62 XIII. TROUBLE SHOOTING (continued) 3. Control locks out after Trial For Ignition (TFI). a. No oil to burner. b. Shorted electrodes. c. Nozzle clogged. d. Airflow too high. e. Ignitor module defective. f. CAD cell defective. g. Oil valve stuck open or closed. Note: The Safety Monitoring Circuit (SMC) is designed to provide lockout in the event of a stuck or welded motor relay. Page 63 XIII. TROUBLE SHOOTING (continued) make sure that they are tight. Also, check the wiring on the boiler against the wiring diagram in Figures 28A, 28B and 28C.

Ensure that incoming 120 Vac power polarity is correct and that the boiler is properly grounded. Possible ErP (External Error) Values: 4. A defective control or component is generally the least likely cause. Before replacing a component, try to rule out all other possible causes. 5. Page 64 XIII. TROUBLE SHOOTING (continued) E. Use BOILER Control Display ??? and ErP Numbers To Direct TroubleShootinG (continued) table 15B: external device (Oil Primary, Option Card, etc.) error numbers Display ErP 4 ErP 5 ErP. ErP 10 ErP 18 Status Warning, Cad Cell Resistance High (service required) No Ignition, Check Cad Cell No Ignition, Check Cad Cell The burner lit very late during the trial for ignition and is susceptible to not lighting. Page 65 XIII. TROUBLE SHOOTING (continued) E. Use BOILER Control Display ??? and ErP Numbers To Direct TroubleShootinG (continued) table 15B: external device (Oil Primary, Option Card, etc.) error number (continued) Display Status Recommended Corrective Actions ErP 23 Flame was proven during the valve on delay period. Check the oil valve for proper Flame Out of Sequence, operation. During Pre-Purge If the system does not have an oil valve, set the valve on delay to 0. Page 66 XIII. TROUBLE SHOOTING (continued) F. Use Boiler Control display STA (status) Number To guide TroubleShooting The Boiler Control will flash “???” followed by a number. Ensure there is power to the boiler control. The Oil Primary will enter the Hard Lockout mode when the burner fails to light, loses flame during run three times or senses flame during pre-purge or post purge. Should you require assistance in locating a U.S. Boiler Company Distributor in your area, or have questions regarding the availability of U.S. Boiler Company products or repair parts, please contact U.S. Boiler Company Customer Service at (717) 481-8400 or Fax (717) 481-8408. Page 70 Bare Boiler Assembly XIV. Page 71 XIV. Repair Parts (continued) Item No. Description Part No. Page 72 Jacket Assembly XIV. gunthermele.com/userfiles/files/Drivers-Manual-Study-Guide-Ma.pdf

Page 73 XIV. Repair Parts (continued) Item No. MPO-IQ84 MPO-IQ115 MPO-IQ147 MPO-IQ189 MPO-IQ231 2. Page 74 MPO-IQ84 Thru MPO-IQ231 Water Boilers - Trim and Controls XIV. BCB7702 100052-01 1 --- --- --- --- MPO-IQ115 Spec No. BCB7707 102065-01 --- 1 --- --- --- MPO-IQ147 Spec No. BCB7703 100053-01 --- --- 1 --- --- MPO-IQ189 Spec No. BCB7704 100054-01 --- --- --- 1 --- MPO-IQ231 Spec No. Page 76 XIV. Repair Parts (continued) Item No. MPO-IQ84 MPO-IQ115 MPO-IQ147 MPO-IQ189 MPO-IQ231 4. Page 77 XIV. Repair Parts (continued) Item No. MPO-IQ147 MPO-IQ189 MPO-IQ231 5. Page 78 Beckett AFG Burner XIV. Page 79 XIV. Repair Parts (continued) BECKETT AFG OIL BURNER PART NOS. FOR MPO-IQ SERIES BOILERS NATURAL DRAFT APPLICATIONS NOTE: When ordering parts always give the serial and model numbers shown on the boiler and burner. Also provide the name of the part(s) and part number as listed below. Page 80 Beckett NX Burner XIV. Page 81 XIV. Repair Parts (continued) BECKETT NX OIL BURNER PART NOS. FOR MPO-IQ SERIES BOILERS DIRECT VENT APPLICATIONS NOTE: When ordering parts always give the serial and model numbers shown on the boiler and burner. Also provide the name of the part(s) and part number as listed below. Item No. Page 82 XIV. Repair Parts (continued) RIELLO OIL BURNER PART NUMBERS FOR MPO-IQ SERIES BOILERS NOTE: When ordering parts always give the serial and model numbers shown on the boiler and burner. The IQ Control System fully integrates both factory and field installed components, simplifying installation and troubleshooting. When installed into the IQ Option Panel, IQ Option Cards provide plug-'n-play high temperature limit, low water cut-off and outdoor reset controls. High Limit IQ Option Cards plug into the IQ Option Panel and connect to a system-mounted probe with a single Molex connection. High Limit IQ Option Cards feature an adjustable set point and differential, as well as built-in diagnostics. Collar Water Content (gallons) Approx. With over 20 years experience, our certified service technicians are all licensed and bonded. Welcome! Here are the website rules, as well as some tips for using this forum. If you've found help here, check back in to let us know how everything worked out. It's a great way to thank those who helped you. Need to contact us? Visit. And more importantly, I didn't get to run my plan by you guys first. I chose a Burnham MPO-IQ 147 with Outdoor Reset, and an installer I'd worked with before, and was happy with his work. I'm pretty happy with the install, and the heat seems more even. It's certainly quieter and much more easy to live with. I'd be so grateful if some generous eyes could look over the install and point out any potential issues before the inspection on Monday, and anything I should ask the installer to tweak before I send the final payment and zip things up. I've included some pictures below. I can take specific pictures of anything you think is worth a second look. My system is 4 zones and DHW. When a call for heat comes, it can take up to 10 minutes to reach 130F. As near as I can measure with my infrared gun, the return temps on the manifold continue to be near 110F at that point. Any issue with that? Maybe a few more pics that show as much as possible in each frame. Was a combustion analysis done with a digital analyzer. What size is the boiler. What's the heat loss of your house and how much radiation do you have? Looks like you might have a single pump with zone valves and a bypass. If so consider at least a thermostatic tee instead of just a bypass, even if you don't go full primary secondary. EDIT2 Looks like your bypass is on the wrong side of the pump. It will just allow flow to go around the boiler. You want to have pumped hot water re-enter your return to warm it up. EDIT3 Looks like the bypass is installed as per the manual. But it is ineffective at raising the return water temperature. If you have prolonged low return water temperature, you may want to switch to a primary secondary arrangement, with some sort of boiler protection strategy. In your case, you would simple connect the supply and returns together near the boiler with a set of closely spaced tee's in the bridge. Then install a boiler pump on the outlet of the boiler and a thermostatic tee on the return (and outlet of the primary boiler pump). This will allow the boiler to quickly come up to temperature by decoupling the load (hot supply goes around in a circle in the primary loop until the return is hot enough). There are a bunch more ways of doing this, each with there own pro's and con's. The expansion tank is connected at the bottom left. I think you may be asking in relation to pump location. Pumps are now pumping away I'll try and capture that in a picture. Combustion analysis has not been done yet, due to time constraints. System is in and heating the house again, and I'll get someone to come and fine tune the burner. Let me go and get more pictures. I've definitely seen mostly BX on the nice photos of work I've seen on here, come to think of it. Intuitively, your suggestion was what I thought, and makes more sense to me.The bypass (as drawn) won't lower entering water temperatures, it just lowered flow rates. I guess the flue temp will go up as the flow goes down since the the average temp in the boiler will be higher. Have you adjusted the flow to give you a certain temp delta. Sounds like you should target a temp delta on the higher end of the suggested range due the extended low return temp period. If you don't get the target delta just by opening the bypass fully, you may have to throttle the boiler valves (below the bypass) a bit, especially since the bypass is undersized. EDIT. looks like you don't have valves between the boiler and bypass. You'll need to add the valves and or properly size the bypass, or upgrade your boiler protection strategy to something more capable. Plan B (a bit of hail Mary) would be to reduce pump speeds to reduce flow. That sounds nuts. The valve is fully open, so I can't get a higher flow through the bypass when it's piped as is. This will reduce system flow, and increase the boiler delta a bit. It won't be quite as reliant on the bypass. Just to be clear, primary secondary doesn't on it's own guarantee boiler protection. It just provides a good infrastructure to add boiler protection to. It's pretty simple, pure mechanical, and doesn't really on a bunch of controls and sensors, and extra pumps. I don't see a thermometer on the return entering the boiler. Boiler protection with min.The way you're piped is a BOILER bypass. If the bypass loop were on the discharge side of the circulator, then you'd have a SYSTEM bypass. They essentially accomplish the same thing but in a different way. The boiler bypass allows the boiler to heat up quickly by diverting much of the return water back into the supply and thus bypassing the boiler. The system bypass puts much of the boiler's heated supply water back into its return and thus bypassing the system. The downside to this arrangement is that it may deprive the system of its necessary flow rate, particularly if a single circ is used. That's the same temp that Buderus allows with their G20 cast iron boilers. Their G20 is actually flexible and they say condensation is not an issue. IDK if Burnham's is the same. Some further investigation is warranted. Another consideration is that you're zoned and much of the time only one or two zones may be calling. This will reduce the flow rate through the boiler and, to some degree, reduce the possibility of condensation. I would get the flow rates on the ZONES as low as possible. Also, IDK what type of radiators you have or if the system is a converted gravity. If it is, I would disable the ODR feature of the boiler. Here's why: with ODR, the boiler water temp is gonna be kept low with that much radiation. The thermostat will probably be satisfied long before the boiler limit ever is. This will vary with outdoor temp and load. If you're bypass is set correctly and ODR is disabled, the boiler can maintain a high enough temp to prevent condensation while the zone(s) maintain a lower water temp due to the natural reset effect. This only applies if you have a high mass system. If it were my house I probably would have gone with zone valves instead of circulators for zoning and primary secondary piping with an injection pumping setup or I series mixing valve, either would provide boiler protection and eliminate thermal shock risk. I'd also look into Tekmar controls, you can do a lot with them. The main thing that worries me is what kind of HVAC contractor installs and commissions a new system without ensuring safe operation by taking the extra 15 minutes to perform combustion analysis. Did he at least use a smoke pump. Please don't tell me he just looked at the flame and said it's good. It certainly will lower the flow rate to the boiler and increase the delta t across the boiler. Only issues I see are the undersized bypass and lack of valves to adjust the flow through the bypass piping. I am not sure what the code says about using armored cable, but I have always thought it was good practice. Looks to me like CI column rads circa 1950. Definitely much higher mass than a baseboard though. I'll take the suggestion about ODR on board. So far this winter has been so mild in New Haven that the set point has rarely gone higher than the 140 minimum anyway. I wish I could get in touch directly with Burnham to get an answer to questions like this, but their website is pretty clear that homeowners need not apply It certainly will lower the flow rate to the boiler and increase the delta t across the boiler. I agree, reducing flow will increase the average temperature in the boiler,but do nothing to raise the return temp, which will reduce condensing, but as long as the return temp is low you may get localized condensing in the heat exchanger. I think the bypass shown is a bandaid that represents a token bare minimum response to protect the boiler. Undersizing the bypass and omitting the boiler isolation valves dooms a strategy that is barely adequate to begin with. My plan for January was actually to re-do it's controls with a Tekmar house control. The only reason I hadn't done that yet was that it was complicated by the fact that the existing circs.I was a bit surprised about the lack of combustion analysis too. I'll just leave it at that. It doesnt make it right. If the load and flow of the zone can be met with the smaller pipe why would you buy larger? Yours is a boiler bypass and it looks like your guy confused the size with a system bypass. But the boiler bypass reduces flow allowing the boiler to heat up quicker. As far as return water temps go, I've spoken with the system designer at the supply house, and he assures me he's spoken with Burhnam about the values I've given him, and things should be fine. Apparently the MPO has some mixing fanciness in how the return water is injected into the boiler that allows it to deal with low return temps. Finally, I had a burner guy who's familiar with Burnhams in particular come out and do an analysis. Numbers are:So, the numbers don't seem at all bad to me. In particular, flue gas temp and draft seem ok, so I'm happy to leave it as is, and look out for any signs of issues at next year's service. What do you guys think? The electrolysis between the brass and malleable pipe and fittings is very minimal, and is a common practice when installing hot water heating systems. If this where a drinking water piping arrangement then a dielectric type fitting is always recommended between two foreign metals.