Replace single wall vent for furnace / water heater with double wall?

[mikepgh]

Home inspector cited the following as a code violation saying the wye pipe for the furnace and water heater is too close to the header above a pair of bifold doors. Said the single wall pipe should be replace with double wall.

Here are some pics. House is 13 years old and has a 2 year old Bryant 80% unit and new Rudd water heater. Basement was finished sometime after the house was originally built.

Can I simply go to Home Depot and pick up a double wall wye pipe? Does this have to be a B Vent?

Thanks.

[docholiday]

First off, it should be double wall anyway and second you need a minimum of 6" clearance to single wall pipe to combustables.

[hvac hero]

Your going to have trouble finding a double wall wye at home depot. I would be calling the company that put the furnace in if its only 2 years old. When we install a furnace, we bring the whole setup up to code. & if that means replacing the vent pipe (which it usually does) then its included.

[mikepgh]

I called the contractor back who put the furnace in two years ago (large outfit in the Pittsburgh Area). They're telling me that in a controlled space it only needs 1" minimum clearance for single wall pipe. They also said the max temp the vent gas reaches on my unit is 250F...more like 190F typically. They said that they would have replaced the pipe during install if it was necessary.

Anyway, could the 1" deal be some sort of local code to this area. Or should I be calling another contractor?

[hvac hero]

In our area a double wall pipe requires a 1 inch clearance. Doc said that you needed a 6 inch clearance for single wall. I know nothing about the clearance for a single wall because we're never allowed to do it.

If the home inspector is raising this question then the hvac company should be able to give you a letter saying they did it according to code & that everything is ok.

[RoBoTeq]

To reiterate; should be "B" vent all the way to the furnace. This would satisfy the code for clearances and the need to keep the flue gases as warm as possible to aid the function of the furnace.

[appltech1]

It doesnt look like you have a 1 in clearance in the picture. Might be time for the city or county inspections dept. You wont have any trouble getting it taken care of if they get involved. Was it ever inspected is a good question.

[BaldLoonie]

National Fuel Gas Code says single wall must be 6" to combustibles. Call your city inspector's office and see what they say. If they agree, ask them to inspect the job and see if the work passes.

[mikepgh]

I'm having a new HVAC contractor come out later in the week to do an annual service on the furnace and inspect the vent piping. I've done some research and found that they make flexible B vent pipe. It looks to me like it would be very easy to get rid of all the rigid pipe between the furnance / water heater and the main vertical stack that goes through the first floor. That isn't pictured above but it is B pipe with a fire stop. A new B wye pipe and some flex B pipe should allow everything to be placed further to the left in the top picture and well away from everything.

Thanks for the replies!