Lack of Hot water

[itchy_wheels]

We have a "new to us" 2000 motor home with a gas-only 6 gal hot water heater. Because there wasn't enough hot water to take a quick shower, we added the electrical rod to it. However, there is not a difference in the amount of hot water when taking a shower. It seems to be maybe a pressure issue? When the hot water is turned on, the pressure is strong but in just seconds the pressure dwindles to very low. When I add cold water to the mix, I have to have the hot almost all the way open and very little cold water turned on. What could be causing this problem?

[naturist]

It's a simple fact that no matter how you heat the water, 6 gallons is not going to afford anybody a long hot one. We, too, have only a 6 gallon water heater, and have had no issues doing two or even three showers after washing the dishes. The trick is what's called a Navy shower: get the water going, wet yourself down, and shut off the water. Soap up, and rinse off.

You, however, may find satisfaction by replacement of the 6 gallon WH tank with an on-demand water heater. They do make them for RVs.

[Dakota98]

itchy wheels wrote:
When the hot water is turned on, the pressure is strong but in just seconds the pressure dwindles to very low.

Pressure obviously builds up when the valve is closed for any length of time. Since this coach is 14 years old, either the check valve at the HW tank or bath faucet is restricted.

As others have asked. Does this happen at other faucets in the coach. If so, the check valve is the likely restriction & needs replacement.

[coolmom42]

Do you have this issue anywhere except the shower? If not, it could be a problem with the shower mix valve.

As others mentioned, check the hot water temp & flow at a sink faucet. That should be informative.

If the problem is at sinks AND showers, then start to look for an issue with the water heater valves.

You should have more than enough hot water to run for 3-4 minutes at a time, for sure, not just a few seconds.

[sch911]

Accidental double post!

[sch911]

Are the outside shower knobs on and the shower head in bypass?

[cmoecmoe]

Just a quick thought... Is there a winterization bypass on the water heater?

If so, there should be 3 valves. For summer use, the top one (hot water out) should be on, the bottom one (cold water in) should be on and the one in the middle (the bypass) should be off. For winterization, all the valves should be the opposite.

Craig

[midnightsadie]

the water pump is coming on??

[midnightsadie]

could be your expecting more than it can handle, rv showers are quicky showers get soaped up rinse off. or by pass valve is open and your water is mixing before the shower head gets the water, go to a sink turn on the hot and read the temp should be 130 or better. that will tell you the tank water temp.

[Old-Biscuit]

Could be the check valve in hot outlet nipple on backside of WH tank (top) is plugging up and restricting flow.
Could be your shower fixture........lots of them have flow restrictors built into handle or head (some can e removed/some have to be drilled out to enlarge hole)


The OEM propane heating is more efficient and has quicker recovery time for heating water. Even better than an OEM electric element. BUT way better than that added heat rod. They are very small wattage and have long recovery times.

Turn them both on for maximum heat recovery.

And RV WHs have to heat the water to high temps (140*F) in order to provide the nominal 6 (or 10) gallons------by mixing cold water to really hot water to extend hot water usage and be delivered by a smaller package