Peerless Boiler Problem

Brad White_203

Said with no amount of understatement...

The coincidence of the installation aside, it seems that you need a positive source of combustion air, an interlocked fan in a can or something, even an open window for now.

A possible cause, more for intellectual curiosity for now, is that the smaller venting water heater probably pre-warmed the chimney to establish draft, however slight. Now when your boiler starts like that, it is into a cold chimney and cannot do the job to get started, just a thought.

An alternate thought: The tankless unit probably has three to six times the venting requirements of the old one which does not allow both appliances to vent properly.

Rather than surmise, get a pro in there pronto and check draft, ambient air for CO (CO2 is one thing, CO is QUITE another), the venting arrangement and vent size..

Think "Red Tag" until you get this resolved. Please get going on this before you stop for coffee.

Brian_73

Peerless Boiler problem

I have a peerless boiler that every time the boiler kicks on the heat comes pushing out of the front of the boiler and ultimately trips the safety device that prevents CO2 from entering the room. This all began the day i had a tankless water heater installed and eliminated my older 40 gallon water heater. The new tankless water heater is a direct vent unit, but the older unit vented into the stack that the boiler vents through up and through the chimney...i hope this makes sense....all help is appreciated...one more thing, if i open a basement window while the boiler is on and pushing the heat through the front, the heat flow then in turn goes up and through the chimney vent and all is well....very strange! What possibly can be causing this?

Big Ed_4

Open Window and Problem Stops??

If so ... You need proper fresh air venting for combustion.

Brian_73

The direct vent water heater is off to the side of the boiler and vents directly through the block foundation of the house...where the older water heater connected into the chimney stack, the plumber just put a cap on where it tied in...this seems to make sense about the older water heater creating draft with the warm air, because when i go down to see if is properly venting, of course before the boiler kicks in, i can feel cold air pushing down on the chimney stack through the front of the boiler.

Brad White_203

Do you also have

a source of exhaust, either kitchen, bathroom or laundry, or something more constant?

To have a predictable down-draft, cold air coming down your chimney pretty much any time you seek it, is a huge concern to me. You may well have another natural chimney not accounted for somewhere.

Not a true chimney per se, but a culmination of factors creating a negative pressure in your basement.

This may be readily identifiable or it may take something like a blower door test or some means to at least identify and account for the air paths through your house. They are obviously going the wrong way...

Bob Gagnon plumbing and heating

Could the new tankless

Be using air from inside the house for combustion and pulling air down through the chimney. This is a serious matter, don't ignore the problem, and get a couple of carbon monoxide detectors, if you don't have them already. You shouldn't depend only on the spill switch.

Thanks, Bob Gagnon

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Brian_73

The new tankless

water heater direct vents outside the house through the block wall so it definitely uses outside air...from what all of you are saying it sounds like my problem is probably a fresh air deficiency in the basement that is causing this...it makes sense because i have only one window in the basement and it is all the way on the other side of the basement, once i open the window i can feel the air flow in and in turn the boiler starts to vent correctly...does anyone know if i can install some source of fresh air to the boiler through a mechanical device that connect to the boiler?

Big Ed_4

Venting

You would need two fresh air vents to the outside. The square opening on each vent is ..... Total BTU input /1000.