We took our new (to us) 2003 27' Itasca Sunova camping for the first time this past weekend for a shake-down trip, and all systems seemed to work fine except for the shower temperature! When using the shower it was hard to get a stream of constant temp water. It seemed to pulsate with hot, then cold, then hot again. This seemed to have some correlation to the water pump cycling on and off, but not entirely sure as I didn't want to waste water. Is there a pressure regulator somewhere to even out the hot and cold flows so that one isn't stronger than the other when the pump goes on?And the only other issue was that our Jack Russell terrier (Teddy) seemed fixated on "something" in the heater vents (the one in bedroom, and the one in the living area up front). He would stare into the vents and whine/bark as if he knew something was down inside the heater venting! There are no signs of any rodent problems, and we used the heater a lot so I assume anything in there would have been cooked! Is there an easy way to clean out the heater ducting just in case?Of course this dog is known to be a bit crazy, so it may have just been his imagination, or maybe he heard sheet metal expanding/ contracting with the heat flow!Thanks!

I have had the same problem. has to do with the pump pulsing on and off and the pressures changing.How I fixed this.when I set the shower temp.Turn hot water full on and then put the cold water on until you get the desired temp. If the pump starts pulsing before you get it adjusted.. you may have to adjust the pump pressure switch (this is what I had to do) so that it stops pulsating.

So the pulsing pump may the problem, and I should use more water so that the pump runs continuously to even out the hot/cold pressures? Or the fix would be to adjust the pressure switch so the pump comes on sooner with pressure drops? Thanks.

Are you sure the water heater valves are fully turned and also be sure your outdoor faucet handles are both off, not just shut off at the handle head

I'm sure the outside shower knobs are off, but not sure about the hot water valve(s)....are those in the hot water compartment on the outside, or under the bed with the other plumbing?

murraymcleod wrote:I'm sure the outside shower knobs are off, but not sure about the hot water valve(s)....are those in the hot water compartment on the outside, or under the bed with the other plumbing?They are usually on the back side of the water heater. Inside the rv

Shower cycling hot and cold! Pests in heater vents??

20 Replies

wa8yxm
Explorer III
Jan 14, 2015
Many water heaters have a check valve on the outlet, this can cause issues, IF you have a 3-valve bypass system it is not needed, likewise on a 2 valve, if you have a single valve system I'd gut the thign and replace it with a quarter turn valve (or add one)

on the fresh water side of the wather heater (inlet) I have no idea why but some companies put check valves there as well.

These valves can reduce the flow of water when pressure drops, leading to more cold in the line.

page 2: HEVAC

Someone said that since the furnace was used they would have thought any live stuff in the ductwork would have gotten cooked,,, NOT SO, it does not get that hot in an RV system.

Home heat the burner comes on, then when it gets hot the blower

RV the blower comes on , then when air flow is great enough the burner

The result is the RV furnace puts out WARM, not HOT air.
Old-Biscuit
Explorer III
Jan 14, 2015
Shower heads have flow restrictors so pump reaches full discharge pressure and then pressure switch turns pump off.......pressure drops so pressure switch turns pump back on.
This pulsing causes differences in hot/cold water flows.

You could remove restrictors (some are in end of hose where it connects to faucet, some are in end of handle, some have to be drilled larger vs removal)

You could change out shower to an Oxygenics Handheld Shower......may smooth out flow demands.

You could install an accumulator tank on pump discharge which can decrease pump cycling

You could mess with pressure set point....adjustment screw on end of pump head.
BUT depends on type of pump.
DianneOK
Explorer
Jan 14, 2015
Moved from Fulltiming for a better response
azrving
Explorer
Jan 14, 2015
Water heaters
azrving
Explorer
Jan 14, 2015
Grabbed this video it may help
azrving
Explorer
Jan 14, 2015
murraymcleod wrote:
I'm sure the outside shower knobs are off, but not sure about the hot water valve(s)....are those in the hot water compartment on the outside, or under the bed with the other plumbing?

They are usually on the back side of the water heater. Inside the rv
murraymcleod
Explorer
Jan 14, 2015
I'm sure the outside shower knobs are off, but not sure about the hot water valve(s)....are those in the hot water compartment on the outside, or under the bed with the other plumbing?
azrving
Explorer
Jan 14, 2015
Are you sure the water heater valves are fully turned and also be sure your outdoor faucet handles are both off, not just shut off at the handle head
murraymcleod
Explorer
Jan 13, 2015
So the pulsing pump may the problem, and I should use more water so that the pump runs continuously to even out the hot/cold pressures? Or the fix would be to adjust the pressure switch so the pump comes on sooner with pressure drops? Thanks.
alid
Explorer
Jan 13, 2015
I have had the same problem. has to do with the pump pulsing on and off and the pressures changing.

How I fixed this.
when I set the shower temp.
Turn hot water full on and then put the cold water on until you get the desired temp. If the pump starts pulsing before you get it adjusted.. you may have to adjust the pump pressure switch (this is what I had to do) so that it stops pulsating.

Forum Discussion

Shower cycling hot and cold! Pests in heater vents??

20 Replies

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