red light on water heater

[aeriqua]

Should I leave my water heater switch on all the time and assume the thermostat will control temperature? If so, what does it mean when the red light comes on – it's not explained in the manual we got..... thanks

[James Schmidt]

Leaving the water heater switch on or off is optional. The thermostat will control the temp of the water. If you don't want the heater to cycle on and off(which is bothersome at night in cold weater) you can switch it off. The red light shows when the direct spark ingnitor is sparking. It will go out when the heater lights. If for some reason the heater does not light, a safety feature will shut the gas valve off and the red light will blink. If this happens, just turn the switch off and then on again and the cycle will be repeated.
Hope this helps.

[cammur]

I'd add to the above that sometimes it doesn't ignite because during the allowed timing interval it receives more air than gas. Sometimes you need the bleed the lines a bit (by turning a stove burner on for 30 seconds or so) and then things ignite OK (hotwater heater, refer, etc.).

[Condoluminum]

While the general principle of "Red light on - heater has shut off or won't light" is correct, there is one other option we discovered... The heater has a pair of circuits to light main burner based on thermostat, and to shut down in case of "overheated" condition if thermostat fails. Both use blade connectors subject to corrosion, and we discovered ours would light when thermostat wire "jiggled", but not always.. Those are clues that both devices attached to side of hot water tank need to be replaced very soon...

John McG

[alan]

When the red light is on, the water heater is in a "hold" mode, and not heating the water. On my trailer, the water heater seems to be sensitive to the mixture setting (adjustable with a sliding tube on the pipe to the burner). I have fiddled with the mixture and once the water heater is up to temperature, it seems to work ok. This typically means multiple attempts to get the heater to start. I suspect somthing else is coming into play.

[Foiled Again]

The red light will stay on when you've run out of propane. Ask me how I found out..... That was one cccccold shower!

Tin Lizzie

[john hd]

light stays on in failure mode.

loose ground wire on mine. check connections if yours stays on and you have plenty of propane.

john

[SilverCottage]

Our red water heater light has never come on since we got our trailer 4 years ago. Is this something I should check? Any idea where to start?

Thanks.

[AirsDream]

There is some variability in what the "red light" means when it is illuminated. But so far as I'm aware, it will always come on when the water heater experiences some sort of upset so that it is not operating properly.

For example, to test this, I'd bet that if you manually shut off the propane to the whole trailer and then turned the water heater on, it would quickly experience a "flame out" and the "flame proofing" circuit (I guess it is so named bacause it is used by the water heater's computer circuits to "prove" there is a flame) would recognize that the flame was out, would shut the gas solenoid (you should be able to hear it click off) and then display a red light, indicating an upset condition. This assumes you have a direct ignition unit, which seems likely on an '07 machine - though Canadian regulations might lead to a different result.

[fmr.capt.evi]

SilverCottage: mine came from the factory with the wires to the light reversed.

[SilverCottage]

Thanks, I'll check it next time we have it home.

[jerry1939]

Just purchased a 1993 30' Excella. The manual on water heaters shows two brands and both of them show a diagram of the thermostat and how to light the pilot lite. When I look at the heater from outside there are no thermostat control or a place to light the pilot. I have one red light switch in the bath. My question is: Do I have a propane or electric water heater or combo with only one red switch. Is it possible the old thermostat was gas with a pilot lite and has been replaced.

[cwf]

Should be electric and propane combo.

The red light is on when there is a "fault" and initially when turned on.

A fault is a failure to detect a flame due to failure to light. The "dinosaur board" detects "electrical flow" thru the plasma of the flame to "ground" .. Indicating a "flame present" condition so the gas solenoid stays "open".. And the burn continues. If the sensor loses the "electrical flow" it thinks no flame present due to lack of fuel or has been blown out. If blown out, a gas buildup would create dangerous condition so it shuts down all fuel and turns on the "red light".