New Boiler, New Water Heater

B-day (Boiler day) turned into B-week. It took 4 days to install our boiler / water heater system. But it was well worth the wait.

This is our old 50% efficient cast iron 210,000 BTU boiler. I wish I had been home while all the work was being done - I would have loved to show you the boiler sitting on the curb.

This is 2 50% efficient 80 gallon gas water heaters plumbed so the tank nearest you warms the water and tank farthest from you finishes heating the water. In effect then we have one large inefficient water heater - it's either a little hot water or a lot of luke warm water.

I was constantly having to relight the pilot on the one nearest you in the photo. I believe it was back drafting because the dryer in the room would suck so much air and create negative air pressure blowing out the pilot light. We're really lucky the back drafting did not lead to carbon monoxide poisoning.


Now we have a beautiful wall mounted 134,000 BTU 95% efficient condensing boiler. Not only is it more efficient - it's safer because it's a closed combustion system which means minimal risk of CO2 poisoning.

Everything is up to current code. That meant a few more valves and expansion tanks. We're so glad that we now have a mixing valve that mixes the hot water down to a specific temperature - it's an antiscald function.

Our new boiler is perfect - it's a Triangle Tube 175. It puts out 134,000 BTU's. We were shooting for 120,000-150,000 BTU's. The water heater is a Triangle Tube Smart 80 that's heated from the boiler. The boiler gets the call from the water heater - the boiler then pumps water around the outside of an inner water chamber - heating the water within.

This is the first time I've been able to fill up a tub of water with no spells of cold water in between.

You can see all the brackets holding the copper pipe to the walls - this is new and will really stabilize the system.

All condensing boiler systems are designed to cycle more often but at a lower temperature. Old boilers only had two options - burner on full blast or burner off - so when a call came in for heat - it'd run full blast until the zone was satisfied. Newer boilers have the ability to modulate the burner to meet the need - so if the burner calls for heat - the burner adjusts to the need. It heats at a lower temperature more often for a more consistent heat and it saves energy. We've gone from 3 50% efficient gas appliances to 1 95% efficient appliance - we're expecting to cut our gas bill in half and get a rebate and tax credit to boot!

All four zones - one for each apartment - are clearly marked. This makes for easy repair and diagnostic work in the future.

The whole system also has an outdoor reset - so if it's 70 outside (which is a hot day in Alaska) and someone tries to crank up their heat to 80-85 - the system will shut down regardless of the zone's call for heat.

The boiler itself also has freeze protection - below a certain temperature it will ignite and cycle - basically warming itself up. If the water pressure drops below 10 psi, it will also shut off protecting itself from burning up. What a smart boiler!