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View Full Version : Single wall pipe to PVC



Bob Hunt
05-28-2009, 09:48 AM
Ran into this "fix" today on a water heater flue. Original inspection had the single wall pipe into a masonry chimney that had been removed below the roof line and capped. Flue gas had nowhere to go and lots of soot around the draft hood. The sellers have provided this "fix" by attaching the single wall pipe to the furnace PVC flue (see photo below).

Water heater is a Bradford-White Model MI403S6EN12 which does not come up on their web site. Similar model numbers are not direct vent models. Obviously there is no induction fan. I have seen induction fans retrofitted to water heaters for this purpose.

1. Is this "fix" as wrong as it appears to be?
2. Can two direct vent appliances share a single PVC flue? I have never seen it done before.
3. Does anyone know of a source for retrofitted induction fans? I guess that my Google search is not using correct terms.

Jerry Peck
05-28-2009, 10:01 AM
1. Is this "fix" as wrong as it appears to be?

Yes.

Cannot answer your other two questions.

Bob Harper
05-28-2009, 10:04 AM
Q1- it is worse than just wrong. Mechanically vented furnace can vent through draft hood into home. This is a death trap and should be immediately disabled, locked out and the homeowners properly notified in writing.

Q2- one appliance per vent

Q3- they sell them but that doesn't make it right. Only if the mfr. offers and OEM kit listed for use with that specific model can you convert to mechanical exhaust. These are mechanical exhaust and not 'inducers'.


Other problems include lack of vent rise, lack of support, tin tape and is that a reduction on the TPR drain?

Good catch!
Bob

Kevin Luce
05-28-2009, 01:02 PM
Ran into this "fix" today on a water heater flue. Original inspection had the single wall pipe into a masonry chomney that had been removed below the roof line and capped. Flue gas had nowhere to go and lots of soot around the draft hood. The sellers have provided this "fix" by attaching the single wall pipe to the furnace PVC flue (see photo below).

Water heater is a Bradford-White Model MI403S6EN12 which does not come up on their web site. Similar model numbers are not direct vent models. Obviously there is no induction fan. I have seen induction fans retrofitted to water heaters for this purpose.

1. Is this "fix" as wrong as it appears to be?
2. Can two direct vent appliances share a single PVC flue? I have never seen it done before.
3. Does anyone know of a source for retrofitted induction fans? I guess that my Google search ius not using correct terms.
:eek::eek::eek::eek::eek:

Rick Hurst
05-28-2009, 05:23 PM
I'd turned off the gas and called the listing agent explaining I was attempting to save these people lives and recommended a Plumber be there today to perform repairs.:eek:

rick

Adam Goodale
05-29-2009, 04:34 AM
2. Can two direct vent appliances share a single PVC flue? I have never seen it done before.

I would think that once another appliance is introduced then the original direct vent appliance ceases to be a directly vented. They don't usually allow regular appliances to share a flue just because it creates another out for the exhaust gases to go which would allow the appliance to vent into the home given the right circumstances.

R. A. Wilkins
05-29-2009, 05:54 AM
That vent is totally wrong. Not only can fumes from the furnace back vent thru the water heater vent and into the home, PVC pipe is not designed to accept high temperatures like the vent would be carrying. When we run into poor venting situations with gas water heaters, we suggest either switching to a power vent type, or an electric type tank. Also in an unrelated matter, it looks like the discharge piping from the pressure and temperature relief valve has been reduced in size from 3/4" to 1/2". This is another no-no since that piping must remain full size, 3/4", to a point with in 6" of the floor or receptor.

Jack Murdock
07-03-2009, 07:24 AM
This should have been red tagged and locked out. Both Fields and Tjernlund make draft inducers with solenoid valves and a safety so that this chimney vent water heater can terminate horizontally. It can never be vented into PVC. Costwise the homeowner would be better served with a power vented water heater