venting gas water heater

morgan

In the state of Mass. can a 3" gas water heater be connected to a 4" vent line from a gas furnace with a 4"x4'x3" "y" pipe or does the gas pipe have to go into the chimmny seperate. The reason i'm asking is the water tank was replaced in a coworkers house. The new one is taller and now the vent pipe pitches down insted of up. A service tech. from the local gas co. who was doing a PM said he could do this. Is this safe.

Thanks for any input.

ed wallace

venting water heater

no its not right vent should never run downhill is the furnace an 80 percent or 90 percent effiency furnace is the chimney lined

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Bob Harper

heat flows downhill?

You know, its hard enough getting water heaters to vent properly anyway. Pitching the pipe downhill violates the NFGC and IFGC, NFPA 211 and common sense. I wish they'd outlaw those Tallboy water heaters! I see it all the time where the installer cut down an elbow just to vent level. No vent rise to speak of. Bad design.

Manifolding is allowed in most areas but the State of Taxacheusetts isn't a normal state. However, when the pipes enter a chimney flue directlty, they are supposed to be offset with the smaller above the larger and the larger can be no more than 7x the smaller in cross sectional area.

In your case, I'd tell them you need to exchange the water heater for a shorter one with some vent rise and connect it to a liner.

PLUMBERPIERCE

venting

In Mass the code for common venting of atomaspheric gas fired equipment is the common flue must be 100% of largest plus 50% of all others...so 4" equals 12.56 square inches and 3" equals 7.07 so 100% of the 4 added to 50% of the three 3.53 that equals 16.09 so 5" equals 19.6. So you need 5" tee and a 5"x4" reducer and a 5"x3" reducer. however if the equipment is fan assisted thats a different story they must connect separately to chimney, also someone asked about a liner and thats a good point, at a minimum you need a clay or porcelain liner. hope this helped

Weezbo

Bang is not a \"Good \"sound.

turn the water heater off plug the opening to the y. a plate exchanger and a pump and a new zone off the boiler would be a"fix"...

oops Furnace...bag that idea. turn it off.get someone over there to install an appliance correctly .call it good.