Water Heater Question

Feb 23, 2008 11 Replies

Does the venting of a water heater have to be vented separately or can it be vented through the furnace? What are the effects if it is, if any?



Thanks Bg


Check your local code. Years ago it was common to vent into the same chimney but now it seems they want everything on its own.

Venting through the furnace is not acceptable. Venting into the same chimney that the furnace vents into *may* be acceptable, depending on your local codes.

The principal effect of improper venting is carbon monoxide entry into the home.

you could buy a direct vent hot water tank that sends its exhaust right thru the wall. more efficent too

What do you mean 'through the furnace'. Many homes have the water heater vent on the same chimney as the furnace. New codes in some states require a separate flue for each device. They are trying to drum up more business and make you pay more.

actually its a safety measure in case one device malfunctions and causes troubles for the other

And what can happen? There are only 2 options. Running and broke.

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flue gasses may back up or not vent well. thats why in many areas furnace must be in seperate flue than hot water tank

both devices may be heating but accidently killing you

Flue gasses may back up with only a single device on the chimney. So what's the point? Both devices are not running at the same time most of the time and it makes no difference if they are.

ide quoted text -

thats the trouble both will run at the same time occasionally.

plus have you ever noticed a hot water tanks chimey is smaller than a furnace?

the device BTU should be sized in regards to the chimney.

to get good draft the chimney must heat up. that takes a long time with a too large chimney

but a furnace on a too small chimney may not exhaust well.

I asked a lot about this after nearly dying after carbon monoxide poisioning....

the chimney cap cracked allowing rain water to get between ceramic liner and bricks, freezing weather expanded the trapped water the flue liner fell in and we all got ill. could of died if a buddy, a volunteer fireman hadnt visited, stayed a while and said lets check the flues. he got it too.

a very close thing

""Blattus Slafaly £ ¥ ? :)"" wrote in message

I'm told it is not just flue gasses, but the potential for some unburned gas too, that could be ignited by the other appliance. Seems it would be rare though. I do know that many homes wee built for many years with both heater and water heater in the same flue.

...

Changing codes and the shift to forced draft instead of natural -- when everything was 50% or thereabouts efficiency w/ natural draft there wasn't much problem. 80% and above require forced draft.

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