Water Heater Problems

[SMarquez]

I have an Atwood water heater that has been acting up for a while now and I hope you can help. It is a pilotless unit if that makes a difference. When I first turn the WH on it takes a couple attempts to light and everything is fine. After 6-7 hours it shuts off and I get the red light at the switch and it won't relight. Once in a while it will try but it seems to struggle and will back fire with a nice POOF that is a little alarming bit doesn't ignite. If I shut it down for a couple hours it will light up like normal. I have taken to just shutting it off when we're not using it but I hate when my stuff doesn't work as designed. I took an air hose to it and got some dust and fine dirt out of it but I lit it up left it on evernite and it shut itself off again. I'm thinking it may be the igniter, maybe it is intermittent or are they a good or bad function only?
Thanks.

[nayther]

Old-Biscuit wrote:

A roll out sensor is just that, it senses excess heat and opens the circuit via a thermistor. There to prevent fires on some heaters. If we knew what heater the OP has it would help.

Roll out sensor......
That is a 'Thermal Fuse' that is OUTSIDE of the combution chamber
IF flame should blowback out of combustion chamber it should trip the 'thermal fuse' (burns out at 190*F----one shot device)
Atwood uses them. Suburban doesn't

That is completely different then the 'Flame sensing' which is done via flame rectrification (AC Current to DC Current) which involves the Spark Electrode and Circuit Board (Used by Atwood & Suburban)

yes, that is what I was referring to.

[Old-Biscuit]

A roll out sensor is just that, it senses excess heat and opens the circuit via a thermistor. There to prevent fires on some heaters. If we knew what heater the OP has it would help.

Roll out sensor......
That is a 'Thermal Fuse' that is OUTSIDE of the combution chamber
IF flame should blowback out of combustion chamber it should trip the 'thermal fuse' (burns out at 190*F----one shot device)
Atwood uses them. Suburban doesn't

That is completely different then the 'Flame sensing' which is done via flame rectrification (AC Current to DC Current) which involves the Spark Electrode and Circuit Board (Used by Atwood & Suburban)

[nayther]

Old-Biscuit wrote:

nayther wrote:

Old-Biscuit wrote:

nayther wrote:

SMarquez wrote:

nayther wrote:
can you hear the spark igniter "clicking" when it tries to light?

I'm with Old-Biscuit, seen quite a few boards being replaced.

Year of TH would be helpful

Yes, I can hear the igniter clicking. It will sometimes "backfire" but not light unless I shut it down for a while.

There's definitely an issue with your heater if you're hearing blowback. Check the main burner tube and where the burner injector tube enters the large burner tube. Spiders love to build nests and webs in these tubes and there's not enough pressure to blow them out. A small wire from a wire brush should pass through the actual gas jet, the other tubes are large enough to use a flexible brush or similar.

There's a sensor that senses flame when it "rolls out" of the burner, it's called a roll out sensor! Could be that's what's happening.

DO NOT go poking ANYTHING thur the orifice......EVER!
THat orifice is a METERED hole that controls the required amount of gas flow.
Poking anything even blowing thru it with High Air Pressure can damage it.
NO!
Soak in alcohol and air dry to clean

you can easily clean an LP jet with a soft bristle from a brush. You're not going to damage a brass jet with a thin piece of bristle, calm down. You're not reaming it out. I've cleaned/unclogged many in this manner.

Are you aware that some orifices used in RV Appliances have thin mica flim with a drilled hole or a ruby gem with a laser cut hole???
Better to KNOW that poking anything thru it CAN Damage it...even the use of High Pressure Air can dislodge the membrane/gem

So best to just NOT do it and just soak/air dry it then cause more problems when it is just uncessesary
**It's not a cutting torch tip

And WHAT is a 'roll out' sensor?

Indeed was not aware, have not seen anything in the orifice before.

A roll out sensor is just that, it senses excess heat and opens the circuit via a thermistor. There to prevent fires on some heaters. If we knew what heater the OP has it would help.

[Old-Biscuit]

nayther wrote:

Old-Biscuit wrote:

nayther wrote:

SMarquez wrote:

nayther wrote:
can you hear the spark igniter "clicking" when it tries to light?

I'm with Old-Biscuit, seen quite a few boards being replaced.

Year of TH would be helpful

Yes, I can hear the igniter clicking. It will sometimes "backfire" but not light unless I shut it down for a while.

There's definitely an issue with your heater if you're hearing blowback. Check the main burner tube and where the burner injector tube enters the large burner tube. Spiders love to build nests and webs in these tubes and there's not enough pressure to blow them out. A small wire from a wire brush should pass through the actual gas jet, the other tubes are large enough to use a flexible brush or similar.

There's a sensor that senses flame when it "rolls out" of the burner, it's called a roll out sensor! Could be that's what's happening.

DO NOT go poking ANYTHING thur the orifice......EVER!
THat orifice is a METERED hole that controls the required amount of gas flow.
Poking anything even blowing thru it with High Air Pressure can damage it.
NO!
Soak in alcohol and air dry to clean

you can easily clean an LP jet with a soft bristle from a brush. You're not going to damage a brass jet with a thin piece of bristle, calm down. You're not reaming it out. I've cleaned/unclogged many in this manner.

Are you aware that some orifices used in RV Appliances have thin mica flim with a drilled hole or a ruby gem with a laser cut hole???
Better to KNOW that poking anything thru it CAN Damage it...even the use of High Pressure Air can dislodge the membrane/gem

So best to just NOT do it and just soak/air dry it then cause more problems when it is just uncessesary
**It's not a cutting torch tip

And WHAT is a 'roll out' sensor?

[nayther]

Old-Biscuit wrote:

nayther wrote:

SMarquez wrote:

nayther wrote:
can you hear the spark igniter "clicking" when it tries to light?

I'm with Old-Biscuit, seen quite a few boards being replaced.

Year of TH would be helpful

Yes, I can hear the igniter clicking. It will sometimes "backfire" but not light unless I shut it down for a while.

There's definitely an issue with your heater if you're hearing blowback. Check the main burner tube and where the burner injector tube enters the large burner tube. Spiders love to build nests and webs in these tubes and there's not enough pressure to blow them out. A small wire from a wire brush should pass through the actual gas jet, the other tubes are large enough to use a flexible brush or similar.

There's a sensor that senses flame when it "rolls out" of the burner, it's called a roll out sensor! Could be that's what's happening.

DO NOT go poking ANYTHING thur the orifice......EVER!
THat orifice is a METERED hole that controls the required amount of gas flow.
Poking anything even blowing thru it with High Air Pressure can damage it.
NO!
Soak in alcohol and air dry to clean

you can easily clean an LP jet with a soft bristle from a brush. You're not going to damage a brass jet with a thin piece of bristle, calm down. You're not reaming it out. I've cleaned/unclogged many in this manner.

[Old-Biscuit]

nayther wrote:

SMarquez wrote:

nayther wrote:
can you hear the spark igniter "clicking" when it tries to light?

I'm with Old-Biscuit, seen quite a few boards being replaced.

Year of TH would be helpful

Yes, I can hear the igniter clicking. It will sometimes "backfire" but not light unless I shut it down for a while.

There's definitely an issue with your heater if you're hearing blowback. Check the main burner tube and where the burner injector tube enters the large burner tube. Spiders love to build nests and webs in these tubes and there's not enough pressure to blow them out. A small wire from a wire brush should pass through the actual gas jet, the other tubes are large enough to use a flexible brush or similar.

There's a sensor that senses flame when it "rolls out" of the burner, it's called a roll out sensor! Could be that's what's happening.

DO NOT go poking ANYTHING thur the orifice......EVER!
THat orifice is a METERED hole that controls the required amount of gas flow.
Poking anything even blowing thru it with High Air Pressure can damage it.
NO!
Soak in alcohol and air dry to clean

Burner tube...swap it out with small bottle brush
Make sure the 'flame spreader' (round disc on end of tube) is parallel with end of burner tube

Flame Proving....
That is done via the Spark Electrode
It provides the High Voltage SPark to ignite the gas BUT is also uesd to sense the DC current that is caused by FLame Rectrification so electrode must be engulfed in flame when gas ignites

Spark Electrode GAP for proper spark and flame proving should be 1/8" - 3/16"

[nayther]

SMarquez wrote:

nayther wrote:
can you hear the spark igniter "clicking" when it tries to light?

I'm with Old-Biscuit, seen quite a few boards being replaced.

Year of TH would be helpful

Yes, I can hear the igniter clicking. It will sometimes "backfire" but not light unless I shut it down for a while.

There's definitely an issue with your heater if you're hearing blowback. Check the main burner tube and where the burner injector tube enters the large burner tube. Spiders love to build nests and webs in these tubes and there's not enough pressure to blow them out. A small wire from a wire brush should pass through the actual gas jet, the other tubes are large enough to use a flexible brush or similar.

There's a sensor that senses flame when it "rolls out" of the burner, it's called a roll out sensor! Could be that's what's happening.

[SMarquez]

Old-Biscuit wrote:
Flame not relighting when t-stat calls for heat (over 6-8 hours it would cycle SEVERAL times) is #1 reason RED Fault Light comes on

If thermostat was going bad it would either NOT heat at all or would overheat
ECO would then trip and lockout water heater (trigger the RED Fault Light)

What year is this water heater?

Sounds like the circuit board is causing problems.....which Atwood boards have an issue with

Good info there. My water heater from 2006 and is a gas only unit. I'll try to post a picture of it. The water heater manual is the only one I don't have from when I bought the trailer new. I'll try to post a picture of it. Thanks.

[SMarquez]

nayther wrote:
can you hear the spark igniter "clicking" when it tries to light?

I'm with Old-Biscuit, seen quite a few boards being replaced.

Year of TH would be helpful

Yes, I can hear the igniter clicking. It will sometimes "backfire" but not light unless I shut it down for a while.

[momentum_rv]

The gap in the ignighter may be too close or too far. Either one can cause your problem. Try adjusting it slightly further to get a stronger spark.

[nayther]

can you hear the spark igniter "clicking" when it tries to light?

I'm with Old-Biscuit, seen quite a few boards being replaced.

Year of TH would be helpful

[Old-Biscuit]

Flame not relighting when t-stat calls for heat (over 6-8 hours it would cycle SEVERAL times) is #1 reason RED Fault Light comes on

If thermostat was going bad it would either NOT heat at all or would overheat
ECO would then trip and lockout water heater (trigger the RED Fault Light)

What year is this water heater?

Sounds like the circuit board is causing problems.....which Atwood boards have an issue with

[Rover_Bill]

Sounds like the thermostat may be going bad and the ECO may be shutting down the gas flow. See this for a nice visual troubleshooting/replacement guide.

[SMarquez]

SDcampowneroperator wrote:
Whats your altidude? Altitude makes a difference in % of air to gas mix, so a lean or rich mix will cause mis fire. When it does light what does it sound like look like?
A roaring flame is lean, lazy lean, quiet, yellowish. Clean blue with slight rumble is proper.
We have had to adjust the air intake (with tape over a bit of the intake) at low altitude to stop flame out from low mixture.

I'm at about 1500'. Everything looks good. Just seems like it won't cycle back on when the water temp drops after the initial start up.