Help with water heater

With the warmer weather here I decided to unwinterize my coach last night. I fairly new at this as its only the second time I have performed this process. I ran into a problem with my water heater, I attached city water to the coach and put the drain plug back into the water heater. I then switched the bypass valve to the normal position. I then turned on the gas supply and and the heating unit came on as normal, I then waited a few minutes while the water heated up. This is where the problem arrises, the water does not seem to be filling the water heater, I verified this by removing the drain plug and no water came out. The flame also went out on the heater as well, I am guessing this is a safety feature.
I am not sure where to look next.


Senior Member
Re: Help with water heater

did you open a spickot (hot) while the hot water tank was filling? That way it blows out the air that was/is trapped inside the hot water tank until it is full of water. after you get a steady stream of water running out the hot side of the sink, then turn on the hot water tank again and see if it works.....good luck


Senior Member
Re: Help with water heater

also, don't start any form of heat (electric or gas) until you are sure it IS full of water.
Re: Help with water heater

I left the drain plug out of the water tank thinking I would see water come out from the bottom of the tank. I am getting a steady stream of water from the facet in the "bypass" and the "normal" position.....but the tank is not filling. Unless maybe the tank takes a bit of time to fill? I will try hooking up the city water and just leave things alone for a few minutes to see if the tank fills.
Re: Help with water heater

It should fill without venting the heater. Actually, there is supposed to be an air bubble in the top of the tank and if you vent it, no bubble.

Sounds to me you don't have the valves correct. It will take a few minutes, the smallest tank is 6 gallons. After the valves are correct, open the sink faucet and be patient. When it comes out at the sink, the tank will be full with an air bubble.
Re: Help with water heater

Well I figured out what the problem was with my water tank not filling. When itook the coach into my local motorhome dealer for winterizing they disconnected the lines running to the tank and used a short splicer to loop the two lines together. I am fairly new to RVing but I am baffled why the shop looped the lines instead of just turning the valve to the bypass position and simply draining the tank from outside. Somebody went to an awful lot of work to make the loop, they had to have taken off two panels and the lower connection is in a tight spot.
My question this normal procedure? it seems strange to me, I am thinking that the shop knows I am new (since I bought the coach there) and maybe they were hoping I would come back this spring saying my water heater does not work.......I hope this is not the case.
Anyway, I hooked up the upper and lower line and of course the tank filled right up and Inow have hot water again.
Re: Help with water heater

Sounds to me like someone did not know what they were doing. When a trailer does not have bypass valves, we have a short piece of hose that we connect the two lines together for winterizing with Anti-freeze. We then hook the lines back up to the heater.

Glad you figured it out.