Atwood Furnace starts then stops - sounds water logged

[ependydad]

We were gone all day today with the HVAC system off. We went to start the furnace; the fan would run for a bit and then would stop until we cycled the thermostat off and back on.

I first checked propane out at the change over valve and it’s showing green. I then checked the stove and was able to run all 3 burners for a bit.

I went outside to see if I could see or hear anything funky. It’s late so I didn’t take anything apart and can’t see anything. But I could hear it and it literally sounds water logged.

Here's a video of the noise:
http://www.youtube.com/watch?v=3X4_RXldhA0

I can honestly say I’ve never intentionally listened to my furnace ignite before, so maybe this is normal.

The outside temperature is about 60F. Inside temp says 67F and I’ve set it to 75F. It has rained for almost 24 hours straight- very hard at times. We HAVE used the furnace successfully before for hours at a time.

The 12v fuse seems OK. The LED light does not indicate a problem (though I know they’re unreliable). I pulled the fuse and the furnace doesn’t even attempt to start.

The furnace IS under the edge of a slide out’s slide topper rail that dumps runoff water directly onto it.

Any thoughts?

[time2roll]

You are correct if the pipes to the water heater are capped off. Put a pressure gauge on the water system and try it before and after adding the expansion tank.

[dougrainer]

time2roll wrote:
The expansion tank/accumulator will act same as the air pocket and absorb the increased volume/pressure and avoiding the spike that would otherwise be created by the expanding water. Can be installed anywhere between the pump and water heater. Basically it is a permanent air pocket.

I had an issue a decade ago where the spike in pressure was causing a leak at the pump. Very hard to detect due to the intermittent nature. Dealer failed twice to find the leak.

And yes I did notice a spike in pressure when the hot water was used up and then no water was used while it re-heated and expanded. This is when I realized the issue and found the leak.

I had an apartment building doing the same thing except it has 2x 100 gallon water heaters. I was having leaks soon after the water company required a backflow device on the main water supply. My plumber put a 2 gallon expansion tank on each water heater and the issue stopped. Leak under the slab was costing $4,000+ each time.

I recommend an expansion tank for all closed water systems including your home or the RV. It really works.

I understand your rational. BUT, the problem remains. Once the WATER HEATER air gap is gone and the W/H is heating up, the pop off valve will still seep regardless of the Accumulator. The problem is INSIDE the W/H tank, NOT the Water system. Doug

[dougrainer]

drsteve wrote:

dougrainer wrote:
You need to order from an Atwood supplier a Part Number 32397 updated door gasket. Atwood had a problem with the original door gaskets and this seals better. Doug

This would suggest that Atwood is at least partly responsible for the OP's water intrusion issue, since they admit that their original gasket was inadequate. If water running down the wall from the slide rail was going in, I would expect that any rainwater running down the wall would do the same.

I would contact Atwood about this problem.

You are correct. BUT, Rainwater running down the sidewall is NOT his problem. Rainwater directed to the furnace by the slide cover run off is the problem. Doug

[drsteve]

dougrainer wrote:
You need to order from an Atwood supplier a Part Number 32397 updated door gasket. Atwood had a problem with the original door gaskets and this seals better. Doug

This would suggest that Atwood is at least partly responsible for the OP's water intrusion issue, since they admit that their original gasket was inadequate. If water running down the wall from the slide rail was going in, I would expect that any rainwater running down the wall would do the same.

I would contact Atwood about this problem.

[time2roll]

The expansion tank/accumulator will act same as the air pocket and absorb the increased volume/pressure and avoiding the spike that would otherwise be created by the expanding water. Can be installed anywhere between the pump and water heater. Basically it is a permanent air pocket.

I had an issue a decade ago where the spike in pressure was causing a leak at the pump. Very hard to detect due to the intermittent nature. Dealer failed twice to find the leak.

And yes I did notice a spike in pressure when the hot water was used up and then no water was used while it re-heated and expanded. This is when I realized the issue and found the leak.

I had an apartment building doing the same thing except it has 2x 100 gallon water heaters. I was having leaks soon after the water company required a backflow device on the main water supply. My plumber put a 2 gallon expansion tank on each water heater and the issue stopped. Leak under the slab was costing $4,000+ each time.

I recommend an expansion tank for all closed water systems including your home or the RV. It really works.

[dougrainer]

time2roll wrote:

dougrainer wrote:
As another poster mentioned, Your video shows the Pop off valve seeping. That is NORMAL, if you have lost your air pocket in the water heater. Follow these instructions to restore the Air pocket to stop that drip. Doug

Dripping Pressure Temperature Relief Valve
Weeping or dripping of a pressure-temperature relief valve while the water
heater is running DOES NOT mean it is defective. This is normal expansion of
water as it is heated in the closed water system of a recreation vehicle. The
Atwood water heater tank is designed with an internal air gap at the tank to
reduce the possibility of weeping and dripping. In time, the expanding water
will absorb this air. To replace the air follow these steps:
To restore the air:
1. Turn off water heater.
2. Turn off incoming water supply.
3. Open the closest hot water faucet in the coach.
4. Pull handle of pressure-temperature relief valve straight out and allow water to flow until it stops.
5. Allow pressure-temperature relief valve to snap shut, close the faucet then turn on the water supply.

Or for a permanent solution get a small Shurflo expansion/accumulator tank.

http://www.adventurerv.net/shurflo-accumulator-tank-camper

What happens when the Water Heater DOES lose the air pocket?????? An accumulator tank is not going to stop the loss of the air pocket. MY understanding of this tank is to give steady constant volume pressure on water pump to prevent pulsating when on water pump. Doug

[time2roll]

dougrainer wrote:
As another poster mentioned, Your video shows the Pop off valve seeping. That is NORMAL, if you have lost your air pocket in the water heater. Follow these instructions to restore the Air pocket to stop that drip. Doug

Dripping Pressure Temperature Relief Valve
Weeping or dripping of a pressure-temperature relief valve while the water
heater is running DOES NOT mean it is defective. This is normal expansion of
water as it is heated in the closed water system of a recreation vehicle. The
Atwood water heater tank is designed with an internal air gap at the tank to
reduce the possibility of weeping and dripping. In time, the expanding water
will absorb this air. To replace the air follow these steps:
To restore the air:
1. Turn off water heater.
2. Turn off incoming water supply.
3. Open the closest hot water faucet in the coach.
4. Pull handle of pressure-temperature relief valve straight out and allow water to flow until it stops.
5. Allow pressure-temperature relief valve to snap shut, close the faucet then turn on the water supply.

Or for a permanent solution get a small Shurflo expansion/accumulator tank.

http://www.adventurerv.net/shurflo-accumulator-tank-camper

[ependydad]

maillemaker wrote:
From the video, it looks like your pressure relief valve is weeping. If you completely seal the access panel, where does the weeping water go? Seems to me it will get stuck in the compartment floor like your water intrusion is.



Steve

dougrainer wrote:
As another poster mentioned, Your video shows the Pop off valve seeping. That is NORMAL, if you have lost your air pocket in the water heater. Follow these instructions to restore the Air pocket to stop that drip. Doug

Dripping Pressure Temperature Relief Valve
Weeping or dripping of a pressure-temperature relief valve while the water
heater is running DOES NOT mean it is defective. This is normal expansion of
water as it is heated in the closed water system of a recreation vehicle. The
Atwood water heater tank is designed with an internal air gap at the tank to
reduce the possibility of weeping and dripping. In time, the expanding water
will absorb this air. To replace the air follow these steps:
To restore the air:
1. Turn off water heater.
2. Turn off incoming water supply.
3. Open the closest hot water faucet in the coach.
4. Pull handle of pressure-temperature relief valve straight out and allow water to flow until it stops.
5. Allow pressure-temperature relief valve to snap shut, close the faucet then turn on the water supply.

I didn't realize this air pocket gets lost over time. I'll do that.

Thanks guys.

[dougrainer]

You need to order from an Atwood supplier a Part Number 32397 updated door gasket. Atwood had a problem with the original door gaskets and this seals better. Doug

[dougrainer]

ependydad wrote:

dougrainer wrote:
Good Video. Bad news. Atwood will probably not be responsible for this problem as it is a bad install by the OEM. Yes, the design and run off of the slide cover has caused your water intrusion. The removable door needs to be installed better with a better gasket. DO NOT use silicone to seal the removable door. Your real problem is the vertical mount. It is OK to install vertical, but you must take special care tom prevent water intrusion. Your interior where all the water is, is causing the circuit board to not function. If you dried out the area and the circuit board the furnace would probably run correctly. The furnace will NOT run if you leave the chrome exhaust pipe OFF. You can just insert it into the exhaust metal pipe to run the furnace once it is dried. Without the metal exhaust pipe installed the intake impellor will just draw exhaust gas back into the chamber and snuff out the flame. If it was my unit or my customers unit, I would make and install a drip cap on top the furnace mount to make sure the water could not flow down the side of the furnace from the slide cover. Doug

That's the weird thing- in person, it looks like the circuit board itself is dry. Everything that is wet is below that separation. Everything above it seems to be dry. ...... I think.

My concern is that I don't know who installed the slide topper/awning rail since the unit did NOT come with slide toppers from the factory. I had the dealer (who is now 1000 miles away) install them. If it was the dealer, then I'm basically screwed without a fight to get reimbursed for whatever work has to be done to correct this issue. I'm asking some friends with a Spartan 1245 of the same year as mine.

Any thoughts on how to dry this thing out?

Slide Toppers were installed. That does NOT mean they were incorrectly installed. Nobody expects that the water run off would hit this one particular Furnace mount. So, this becomes an issue. It is NOT the RV OEM's responsibility. It is NOT Atwoods responsibility. It is NOT the slide cover installing dealers responsibility. It is just one of those weird things that happen. Doug

[dougrainer]

As another poster mentioned, Your video shows the Pop off valve seeping. That is NORMAL, if you have lost your air pocket in the water heater. Follow these instructions to restore the Air pocket to stop that drip. Doug

Dripping Pressure Temperature Relief Valve
Weeping or dripping of a pressure-temperature relief valve while the water
heater is running DOES NOT mean it is defective. This is normal expansion of
water as it is heated in the closed water system of a recreation vehicle. The
Atwood water heater tank is designed with an internal air gap at the tank to
reduce the possibility of weeping and dripping. In time, the expanding water
will absorb this air. To replace the air follow these steps:
To restore the air:
1. Turn off water heater.
2. Turn off incoming water supply.
3. Open the closest hot water faucet in the coach.
4. Pull handle of pressure-temperature relief valve straight out and allow water to flow until it stops.
5. Allow pressure-temperature relief valve to snap shut, close the faucet then turn on the water supply.

[Chum_lee]

As a further comment to Dougs post, be careful not to involve yourself too much here. Your RV is under factory warranty. You paid your money. If you can, let them handle it. The more you mess with it, the more reason you give both the furnace manufacturer and the RV manufacturer to blame YOU (absolving themselves) for what's wrong with it. Time is NOT your friend either.

Chum lee

[maillemaker]

From the video, it looks like your pressure relief valve is weeping. If you completely seal the access panel, where does the weeping water go? Seems to me it will get stuck in the compartment floor like your water intrusion is.



Steve

[time2roll]

ependydad wrote:
Any thoughts on how to dry this thing out?

I would use a shop vac to extract the bulk of the water. Then fire it up to dry it out.