I cant seem to get my watter heater to ignite on gas. It works great on electricity but starting friday nite I am going to be boondocking in Colorado and need the thing to run on gas. I cant seem to get it to ignite for anything. I have tryed 30-40 times and I would think what ever air was in the line should be gone buy now. I lit the stove to make sure it was all out of the main line but the thing just wont lite. There isent even any air coming out the orfice/jet in the burner. I tryed a little spitt on the finger and rubbing it across the hole to see and there was no bubbles at all. I even got to the point I litt a click liter in front of it to see if there was any air/gas flowing out of it and the flame dident even flicker. The gas has to go threw an electric solinoid first and it never clicks or anything like it is opening. The unit is brand new and has never been used on gas, just electric. I would take it back to the dealer but they are an hour away and I dont have time before I leave. Any one familiar with these things? What should I try or look for?

 

If the heater has a pilot light, it will usually have a temperature switch located over the pilot light. Your heater will have an override button on it that you push to flow gas until the pilot light has heated the switch to a certain point.
Household heaters are like this, so I asume mobile heaters are the same way.

 

No pilot lite. It has a Electric spark ignition. It has a 15 second purge before trying to ignite itself. Then it sparks for 15 seconds and trys 3 times before giving up. The problem comes in the fact that durring the 15 second purge time there is nothing air or gas comming out of the orfice/jet. I dont know, I may have to take it to the local RV dealer tomarow or the day after to have them check it out.

 

I would make a quick pass over all the lines back to the tank and make sure there isn't a valve shut off somewhere.
then start at the heater and loosen connections until you get gas. I would guess that there is a cob web stopping the line near the heater if the unit hasn't run off gas in a while.

 

Since this is the 1st lighting you most likely have air in the line going to the fridge. Make sure that your gas is on to appliance. There may be 2 valves.

Preheat the thermocoupler above the pilot light housing with a long match or long stick propane fire place lighter. Then try it again.

As a last resort:
I'd crack the gas line and bleed off a little propane at the point closest to the pilot light and try it again. Make sure that you give enough time for the gas to dissipate before lighting or you'll burn up yourself and your rig!

Hope this helps.

Rick

 

The burner on a water heater doesn't run very often, but does seem to move a lot of gas when burning, so it should have purged the air out in a try or two...

The part about not having run it on gas before made me wonder if the manual gas valve is turned on... Most newer water heaters will have a quarter turn type valve, the head of which needs to be in line with the gas line to be on.

The next things I would check: Put a voltage meter across the selinoid and see if it gets 12v when trying to light.

After that, pull the burner and there will be an oraface threaded in there. Clean it with alcohol and compressed air. Don't use a wire. Often ultra-tiny spiders like to climb in there for some reason.

If it's a newer unit, it likely does not have a thermocouple, but uses the same electrodes that light it as a flame sensor, but if that were the problem you would expect it to light for a second or two, then the safety valve would cut off the gas.

There may also be an over-temp cutout, which may have a button on it for "push to reset", that keeps you from burning the thing up if it gets lit w/o water.

 

I will try crakking the lines and see if that does anything. All the rest of the gass apliances work great. The stove, fridge and furnace all fire rite up on gas but not the stinken watter heater. Ille be darned if I am taking cold showeres for a 9 days in Colorado. I cant find the high temp reset switch but I would think if it was tripped niether electric or gas would work.

 

Yeah, check for voltage. It sounds like you aren't getting any power. Is there a circuit breaker panel somewhere? You should be hearing the "electric spark ignition" firing away while it's trying to light in addition to that solenoid click open.

 

I think the problem is the circut board that controls the ignition and operation of the water heater. I checked and there is no voltage at the solinoid but the sparker is going like mad. I traced the wire for the solinod back to the circut board and checked for power there and ther is non. The board has power going to it and it fires the sparker but on the little prong that the wire for the solinods go to there is no power at all. I will try and get a new board on it tomarow and see if that does it or not.

 

You should not have power to the solinoid until it is satified that the pilot is on.. The spark ignitor sparks and lets gas out of the pilot.. When the flame of the pilot lights it completes the circuit and grounds so the spark stops. (flamew recognition). As the power passes through the flame to the ground the control recognizes that the pilot is lit and allows the main burner flame to come on..

you could also have a fluid safety in there.. or a Pilot generator.. If you see a post that the flame heats up then it is a pilot generator.. If you see a small tube (looks like a piece of bailing wire) that goes to a little fluid buld by the pilot then you have to wait until that bulb gets hot and pushes the silocon fluid to open the valve.

Electronic Ignition appliances don't have thermocouples.. thermocouples don't have enough power to open a valve.. that is why you always have to push, pull or turn something to set the safety. (the thermocouple makes enough electricity to energize an electric magnet and you have to push the valve to make ocntact with the magnet head).

 

His unit is pretty new, so I would presume DSI with no pilot light.

 

if your unit is fairly new you probably have an CO sensor as well as a propane sensor. Make sure the 9V battery in the propane sensor(a brown plastic panel, low in the coach) is good. It will shut down all propane to the unit.
tom

 

Can you please post the make/model of your water heater?

 

I know it's already been said. The CO sensor has to be on (that annoying beeping thing near the floor that looks like a smoke detector), so the propane supply solonoid opens and you get get gas to the water heater.

Had the same thing happen once.

 

Ok got the new circut board instaled and nothing. The dealer was positive that would fix it but now its to late to wory any more. I will have to run the generator to power the 110 volt side of it for showers every nite. For those wondering it is a DSI unit NO PILOT LITE. The brand and model number are Suburban Manufactureing, SW6 DE. The circut board controles the solinoid valve that turnes the gas on and the sparker. The sparker is also the thermo couple that tells the circut board that the flame has lit and it can stop sparking. I had a good freind come over last nite that is an electronics maintinece person. He lives and breathes this stuff and he figured out that acording to the wiring diagram there needs ot be a signal sent back to the board from the overheat shutdown switch wich doubles as a thermostat. That is what controles when the flame kicks in and out to keep the watter heated. There is no power coming from them to the board so he is thinking its more likely the overheat switch/thermostat that is bad or the hole unit is wired wrong. The sparker sparks like mad but the solinoid for the gas never opens so we turned the swich on causing the sparker to go and then put a 12 volt source directly to the terminals on the solinoid and it emediatly ignited so the solinoid works, its just not getting power from the board to tell it to open. Oh well it not like I will be taking cold showers. I will just have to run the generator every nite to get hot water. I will definatly be taking it back to them to fix wen we get home.