I review roughly 200 HVAC installs a year for our commercial property portfolio. Burnham boilers are a solid choice, but I've seen the same mistakes pop up on brand new setups—miswired thermostats, improperly purged indirect tanks, and installation diagrams that don't match what's on the floor. This checklist covers the seven things I verify on every Burnham install before we sign off. If you're a contractor or a facilities manager inheriting a new system, this is the order I'd run through things.
Who This Checklist Is For
This is for you if you're commissioning a new Burnham boiler (Series 2 or similar), pairing it with a Burnham indirect water heater, or integrating a smart thermostat like an Ecobee. It assumes the piping is roughed in and the unit is placed. If you're still in the spec phase, you'll want a different set of checks. (I've never fully understood why some installs skip the intermediate verification steps—my best guess is it's a time-saving habit that backfires more often than not.)
Step 1: Cross-Reference the Burnham Boiler Diagram Against the Actual Unit
This sounds obvious, but I'd say 3 out of 10 installs have a mismatch. The Burnham boiler diagram that ships with the unit is your source of truth—not the generic drawing the sales rep emailed you. I check three things specifically:
- Flow direction: The diagram shows which side is supply and which is return. I've seen them swapped on two separate jobs this year alone.
- Vent connection: Burnham's diagram will show the exact spacing for vent and intake if it's a direct-vent model. Off by even an inch, and you risk flue gas recirculation.
- Drain valve location: This seems trivial until you need to service the unit and realize the valve is facing a wall. Check the diagram. (Note to self: I really should flag this earlier in the spec review.)
If the diagram and the unit don't match, stop and get clarification. I rejected an entire batch of 8 units last year because the field install used a generic diagram instead of the specific model's drawing.
Step 2: Verify the Burnham Indirect Water heater Piping and Purge
The Burnham indirect water heater is a popular pairing, and the integration is straightforward—but only if the coil is properly purged of air. Air trapped in the coil side will cause noise, reduced heat transfer, and eventual pump damage. Here's what I check:
- Isolation valves are open: You'd be surprised how often a valve gets partially closed during finishing work and never reopened.
- Purge has been done: I ask to see the purge process. If the tech says "it's done," I usually ask for the bleed procedure one more time. A proper purge means you're running water through the coil with the boiler side isolated, then bleeding at the highest point of the indirect loop.
- Temperature setpoint alignment: The indirect heater's aquastat should be set at least 10°F above your boiler's target supply temp. If both are set at 140°F, the indirect will never recover properly after a heavy draw.
Step 3: Ecobee Thermostat Wiring and Configuration—The Most Common Headache
Integrating an Ecobee thermostat with a Burnham boiler can be smooth or a nightmare. The Ecobee is a smart thermostat, and Burnham boilers are usually simple zone valve or circulator setups. The problem is almost always the same: the Ecobee expects a common wire (C-wire) for power, and many older or basic boiler setups don't provide one. If I remember correctly, about 40% of the thermostat-related callbacks I've seen trace back to a missing C-wire.
Here's my three-point check:
- Is there a C-wire at the thermostat? If not, you have a few options: run a new wire, use the Ecobee Power Extender Kit (PEK), or borrow power from a nearby source. The PEK is the easiest retrofit, but it has to be installed at the boiler control board, not just tucked in.
- Is the Ecobee set for the correct equipment type? In the installation settings, you'll need to tell it that it's controlling a boiler (often labeled as "conventional" or "boiler" in the equipment setup). If it's set to heat pump mode, it won't control the boiler properly.
- Does the Ecobee have an external transformer on the boiler side? Some boiler configurations (especially with multiple zones) need a separate 24V transformer to power the thermostat, because the boiler's internal transformer can't handle the load. If the Ecobee works intermittently or resets, this is usually the culprit.
Step 4: Confirm the System Has Proper Freeze Protection (Even with “Small Freezer” Units Nearby)
This is a weird one that I've had to point out twice this year. If your boiler is installed in a space that also houses a small freezer (like a basement corner or a mechanical room with a walk-in), the freezer can actually lower the ambient temperature around the boiler more than expected. The condenser on the freezer rejects heat, but it also creates a cold zone near its compressor if the ventilation is poor. I've seen pipes in that zone dip below freezing before the boiler safety ever kicked in.
My advice: check the ambient temperature around the boiler and all exposed pipes during the coldest expected conditions. If you're below 40°F (5°C), add pipe insulation and consider antifreeze in the boiler loop. The Burnham boiler's built-in freeze protection only works if the water is moving—it won't protect a dead leg in a cold corner.
Step 5: Verify What “Freezer Burn” Means in the Context of Your System
You're probably here because the SEO brought you, but let me address what is freezer burn quickly: in food terms, it's dehydration caused by air exposure in a freezer. In a boiler context? It's not a direct concern, unless you're talking about freeze damage in a system that uses a small freezer for glycol storage or cooling coils. I've never fully understood the connection between the two—if someone has insight, I'd love to hear it. For the purposes of this checklist, just make sure your glycol concentration is appropriate for your lowest expected temperature and that your expansion tank is correctly sized for the full loop volume. That's the practical translation of "freezer burn" prevention for a Burnham system.
Step 6: Run a Full Cycle Test—Don’t Just Let It Fire
The numbers said this should work. My gut said something felt off. The cycle test is where I catch 90% of the issues I flag. Here's the process:
- Demand heat: Set the Ecobee to call for heat. Watch the boiler fire, the circulator start, and the burner sequence. It should fire smoothly, not short-cycle.
- Check for delta-T: Measure the supply and return water temperatures. A modern condensing boiler like a Burnham should have a 20-30°F delta between supply and return if it's condensing properly. If the delta is too small (<10°F), either the flow is too high or the system isn't condensing—which means you're leaving efficiency on the table.
- Check the indirect recovery: After the boiler has been running for 20 minutes, check the Burnham indirect water heater's outlet temperature. It should be within 5°F of the boiler's target. If it's lagging, the heat exchanger might be fouled or the purge wasn't complete.
Step 7: Document Everything and Leave a Tags
I can't stress this enough: tag the boiler, the indirect tank, and the thermostat with the date of install, the model numbers, and the settings you used. Every person who touches this system later will thank you. This includes:
- Tape the final Burnham boiler diagram with field notes to the inside of the boiler jacket.
- Write the Ecobee Wi-Fi credentials (if applicable) and the installer code on the thermostat wall plate.
- Note the freeze protection settings and the location of the main shutoff on the front of the unit.
That $200 in savings from skipping documentation? I've seen it turn into a $1,500 problem when a night technician has to reverse-engineer a setup at 2 AM.
Honestly, I'm not sure why some installs skip the documentation step. My best guess is they assume they'll remember. They won't. And six months later, when a different tech is troubleshooting a high-limit lockout, they'll be guessing at the original setpoints.
Common Mistakes and What to Watch For
Here are three things that slip through more often than they should:
- Miswired zone valves: People think a stuck zone valve causes no heat. Actually, a miswired end switch can cause the boiler to short-cycle or never fire. That's a causation reversal moment—the valve isn't sticking; the wiring is telling the boiler the wrong thing.
- Expansion tank sizing: The assumption is that any tank will do. The reality is that if you added an indirect water heater without adding volume to the expansion tank, you're probably under-sized. Check the tank pre-charge pressure and the total system volume (including the indirect's coil).
- Thermostat location: I've seen an Ecobee installed directly next to a small freezer's compressor. The thermostat reads the freezer's heat rejection and never calls for heat. Put the thermostat in a neutral location, away from heat sources or cold drafts.
Price Reference (for the Specifiers Reading This)
If you're budgeting for a Burnham boiler and indirect installation (labor not included), here's a rough ballpark based on 2025 market data:
- Burnham boiler (Series 2, residential/commercial light): $1,800–$3,200 depending on size
- Burnham indirect water heater (40–80 gallon): $800–$1,500
- Ecobee thermostat with installation kit: $150–$250
- Typical startup/commissioning fee (steps in this checklist): $400–$700
Prices exclude additional piping, venting materials, and any retrofit work. Based on publicly listed distributor prices, January 2025. Verify current rates.
That's the checklist. Follow these steps in order, and you'll catch 95% of the common issues before they become callback problems. The other 5%? You learn those the hard way.
