York 95 Deluxe Furnace venting problem

[pico]

After my new furnace was installed last week, it kept repeatedly shutting down (low gas pressure error message-8 flashes after only a few minutes and blowing cold air).

We have had three HVAC techs come out now and the third one ended up cutting the intake vent pipe down to 24" and now everything seems to work perfect (except it does not fire on high, only low..)

My question is, can the answer really be this simple? The original vent pipe was 15' long with 2-90 bends which seemed to be as per install specs..is it any problem to run this furance with such a short intake pipe using inside basement air? (it uses 3" PVC pipe as required).

Are these 95 units really this tempermental?

Thanks

[davidr]

It sounds as though the service techs visiting your home are guessing rather than measuring.

How many unresolved issues do you still have with your installation?
Any explanation from the techs why high fire would not operate?

[firecontrol]

I suggest you contact the manufacturer and see if they can, through the wholesaler that your contractor is buying his equipment, send a factory trained troubleshooter.

[contactor]

Thats not the answer. Your furnace should operate fine with the original 2 pipe installation that went to the outside.I assume your saying they cut the intake pipe so now its drawing combustion air from the basement. The furnace is shutting down for a reason 3 techs havnt found,3rd tech found only a solution to get it fired , and its not firing on high. Better call the owner .

[beenthere]

Post the model number.

The tech is just just treating the symtom, not the problem.

[pico]

The model number is p1xuc16n07501c

[pico]

I also wanted to add, the first tech said the gas pressure was low, and asked me to call out the gas company as he thought the gas pressure readings were low when it fired up..(it kept shutting off after five starts each time).

The gas company came out, claimed there was nothing wrong with the gas supply (flow 8.6, lock up 9.6, normlal) is the data he left.

I am also skeptical that shortening the intake was the answer to all this, but now that it works, I really can't question anything at this point, unless it fails again.

What else can I ask them to look at at this point?

Is a short intake that pulls basement air in any way a danger?

[billva]

it's no danger, but the whole purpose of a two pipe system is to use unconditioned outside air for combustion as opposed to conditioned inside air. the inside air used in the combustion process will now be replaced with outside air(through leaks in the home), which will now have to be conditioned, resulting in a slightly lower efficient furnace.

[beenthere]

Originally posted by pico
The model number is p1xuc16n07501c


That furnace needs a min 5' of vent pipe.

Also, that model usually needs a drip tee in the vent pipe, it may not have the newer condensate trap at the inducer.

Does the vent pipe slant down toward the furnace, or toward the wall.

How long is the gas pipe run from the meter to the furnace.
And what size is the pipe.


If it needs a drip tee, and one isn't installed, you will still get an 8 flash error, but it not the gas pressure causing it.

[pico]

There is no drip tee on either of the two pipes.

The pipes are 3" PVC and about 15' long, slanting down towards the furance.

There can't possibly be any obstuctions because the pipes are brand new when they were installed.

[beenthere]

Originally posted by pico
There is no drip tee on either of the two pipes.

The pipes are 3" PVC and about 15' long, slanting down towards the furance.

There can't possibly be any obstuctions because the pipes are brand new when they were installed.


It needs a drip tee.

Doesn't need 3" pipe for that short run with only 2 els.
but it doesn't hurt.

Look in the install manual they should have left there.
It will tell you about the drip tee.

[pico]

would this same vent pipe issue have anything to do with it not firing on high? no complaints, it seems to work fine on low, and if it uses less gas in low, all the better in my opinion.

Is high fire used to heat the house faster? or is there some other reason?

thanks

[justadad1957]

Dont say they cant be restricked, lol I have pulled childrens toys from exposed vents

Playschool tractor

system drove me nuts

[beenthere]

If its sized right.

When its starts getting close to design temp, it won't be able to heat your home on low only.

They may have disabled high fire.

[dngtig]

Is this furnace running on LP or natural gas? I don't think the vent pipe has anything to do with it.If the vent was restricted or blocked you should get a #3 or #6 fault code. Do you have other gas appliances on this line? Someone needs to check gas pressure correctly.They probably disabled high fire at this point so it will run. Go to yorkupg.com and go to find a dealer and get someone else to look at your furnace.

[beenthere]

Originally posted by dngtig
I don't think the vent pipe has anything to do with it.If the vent was restricted or blocked you should get a #3 or #6 fault code. .

Had a couple of them, that our installers thought that the vent was short enough that they didn't need a drip tee.

Got the same 8 flash error code.
Installed drip tee, and no more trouble.

You could hear the inducer slowing down from the condensate running back into it. You could hear the pressure switch open and close right away, so the board didn't register the open switch, just the flame failure/low gas pressure error.