suburban "gas only" hot water problem

[vol ff]

Have a suburban 6 gallon hot water heater that is gas only and has to be lit manually. Pilot light ignites and burns great, but the burner will not ignite at all. All other appliances run by gas work great too. Have installed a new thermocouple to no avail.

Any suggestions??

Thanks!

Vol off
2005 Salem 28bh
2013 F150 Super Crew

[thebrakeman]

Main burner will only light if the thermal sensor has been warmed by thte pilot for a sufficient amount of time. This sensor is right above the little pilot tube. Is that what you replaced or something else.

Once last year I was banging my head against the wall for the same problem. Pilot lit, but no main burner. Went around and check everything. Finally notice that the temperature slide lever was set all the way down. Slid up to normal, and it fired right up. So just be sure you have actually "called for" hot water.

Other that those simple things, I don't know.

[Herk7769]

Look at your high and low limit switches and measure for 12 volt control power at each one. They are located between the pressure relief valve on the top and the combustion chamber on the bottom.

[vol ff]

Thanks for the replies. Still stumped!! Camped this weekend and still bad luck. Pilot light ignites and burns fine. Have a new thermocouple in unit. Main burner ignites only once! Will not stay running long enough to heat water up no matter what temp setting it's set to. My unit is the SW6P that you have to light pilot light with a camp stove lighter and then rotate gas knob to "on". Have NO electronic switches or controls. Temperature setting is a black plastic tab with many holes you adjust on a pin.

Thinking the thermostat/gas valve may be bad?????

[Herk7769]

Originally Posted by vol ff

Thanks for the replies. Still stumped!! Camped this weekend and still bad luck. Pilot light ignites and burns fine. Have a new thermocouple in unit. Main burner ignites only once! Will not stay running long enough to heat water up no matter what temp setting it's set to. My unit is the SW6P that you have to light pilot light with a camp stove lighter and then rotate gas knob to "on". Have NO electronic switches or controls. Temperature setting is a black plastic tab with many holes you adjust on a pin.

Thinking the thermostat/gas valve may be bad?????

The high and low limit switches are actually bellows activated thermostats. You have two. Either one can be bad.

When the tank is cold, BOTH switches must conduct electricity. (easy to check since an ohmmeter will show continuity) .

While I am more familiar with the Suburban models, the procedure below should be similar on yours.

If either one is "open" you will need to try a reset on the high limit one (should have a "button" on it you can press) or replace it if bad.

You are looking at those red terminals between the pressure relief valve and the gas burner in the photo. The "bellows" part of the thermostatic switch is hidden behind the square cover.

[vol ff]

herk7769,
I think mine is a different model than what you showed me. My water heater does not have any of the wiring at all. It has only the gas supply to the thermostat/ gas control?? With a small tube to the pilot light and a copper color tube from the thermocouple.

Mine looks like the model sold in this link:

[URL="http:// http://www.adventurerv.net/suburban-gallon-water-heater-sw6p-p-82.html"

[vol ff]

Sorry, that link didn't work.

Here's a link of an image of my model water heater.

http://caravansplus.com.au/images_ti....6-litre,l.jpg

[BarryD0706]

I used to have one of those. The pilot wouldn't stay lit of the thermocouple was bad.

I'd say either you have some obstruction in the gas line to the water heater (I had a black
liquid in mine), something stuck in the orifice, or you need a new valve. Don't try to clean the orifice with a wire or anything like that or you'll damage it. Try blowing out the orifice with compressed air.

[Herk7769]

OK, looked into this model of water heater and there are only 2 user serviceable parts; the thermocouple and the "gas control."


Suburban 161111 Thermostat Gas Control For SW10P Models and SW6P Models Trailer Camper RV

[jonandjolene]

You might have a spider nest in the pipe. They are easy to remove and clean with a flexible brush. I had an old Coachmen motorhome years ago and everytime we took it out, we had to clean the spider webs out.

[gasman6674]

If the pilot stay lit and the unit lights once then will not stay lit you have a bad control. You might price a new control vs a new heater. The heater might be simpler