The PVC flue pipe from the furnace goes into the chimney along with the single wall flue vent from the water heater above it. Should two different material flue pipes be in the same chimney
No it should not.
4 Likes
Although that looks Ok, it depends on the combustion fuel. In the case of an unlined flue (older home - brick only) a gas appliance (water heater) can no longer share the flue with an oil fired appliance (furnace/boiler). This change caused me to get an electric WH for the older home I grew up in (1911 build). where they had shared a flue for years this was no longer permissible when I needed a new WH.
I concur Martin.
Definitely old and less than ideal setup but you’d need to reference both appliances’ manuals to know for sure if it’s, “wrong.” Years ago I got my nose rubbed in it from an HVAC contractor that installed something similar and it was technically okay. IIRC, there were lots of conditions that had to be met - things like a clay liner in the chimney.
Clearance to the PVC is the obvious issue. That is a steel single wall flue entering the chimney. It requires 6" clearance to combustibles, and while PVC may not technically be combustible in that it cannot sustain a flame, its melt point is 140F. This is an automatic call out for me.
1 Like
Do they actually “share” a flue? Do you have a picture of the top of the chimney? If both are ran separately and just using the chimney for a chase, then as long as the clearance Lon mentioned is maintained, it should be fine (1" if it is b-vent inside the chimney). Of course it might be difficult to verify that clearance for the entire length of the chimney.
4 Likes
^^^ This ^^^
Agreed, that’s the only way to be certain, but IMO, chances lean towards it not being correct.
Do you have a picture of the top of the chimney @dlee2 ?
1 Like