Low Hot Water Line Pressure

[Larry_M]

We just de-winterized for the first time and noticed that the hot water pressure is approximately half of the cold water pressure. The water has not actually been heated up yet since we’re just testing the lines. The water pump does shut off when running from the fresh water tanks (rather than city hookup) so I don’t think there’s any leaks. The hot water line pressure is consistently lower in all faucets and shower. Hot water pressure is also low regardless of fresh water tank / pump or city water hookup. Also, the hot water pressure (again unheated water) was low even with the hot water bypassed so the bypass valve setting doesn’t seem to make a big difference on hot water line pressure.

So, I’m thinking something is clogged at a common point (ie, close to the heater tank) OR is it possible the pressure doesn’t build up until the water is heated?

The AS is a 2020 25’ FC RBT. Suggestions and ideas are welcome!

[DCPAS]

It's the inlet screen to the mixing valve.

https://www.airforums.com/forums/f44...hy-220881.html

[oldenavy]

DCPAS is right, same thing happened to me last year. I replaced the mixing valve and keep the old one as a spare after cleaning the screen as well as I could. Got the new one on Amazon.

[DCPAS]

We have a 2019 25 RBT and had the same problem. Assuming it is the same, the mixing valve is accessed from the road side bed forward storage compartment. Four screws secure an access panel. I tried to remove the mixing valve while camping but didn't have a bit enough wrench. When I got home, I used a wand to rinse the hot water tank and that cleared the debris. There are posts here that go into removing the mixing valve and cleaning it and the inlet screen.

[Larry_M]

What's confusing me is that the low pressure occurs with the bypass valve on or off. Does water always flow through the mixing valve regardless of the bypass valve setting?

[Larry_M]

Thanks. Did you insert the wand via the drain plug? I'm trying to visualize how you go the wand in the tank.

[majorairhead]

This is just me, a novice, but I'd try hooking up to city water and running that, plus the online pump. I'd also make sure to run the outside shower, maybe even open and close the low point drains.

Run everything more than once.

We had some water pressure issues, along with some hot water issues, for a short time, until we got all the air out of the lines.

[DCPAS]

Originally Posted by Larry_M

Thanks. Did you insert the wand via the drain plug? I'm trying to visualize how you go the wand in the tank.

Yes. You remove the nylon plug. This is the wand: https://www.amazon.com/Camco-Rinser-...s%2C173&sr=8-9

And how to use it:

https://www.youtube.com/watch?v=_2pVxM7_jXc

[DCPAS]

Originally Posted by Larry_M

What's confusing me is that the low pressure occurs with the bypass valve on or off. Does water always flow through the mixing valve regardless of the bypass valve setting?

It does. The idea is that it allows you to set the water heater for hotter water and, when mix it with cold water, you get more hot water from the water heater. My brother has a different brand trailer with a similar heater, but it does not have a mixing valve.

Edit: I misread your question. I do not know.

[Wetfeet]

You may also have air trapped in the piping around the water heater, which is a high spot. Try opening the low point drains located underneath the water heater with either the pump or city water hooked up. It is possible to blow the air out using these low point drains, which will restore full hot water flow and pressure.

[Dennis C]

Based on my recent experience, I’d guess that it’s sediment in the filter screen of your mixing valve. My International is only a year old, and we had quite a bit of crud packed into the screen inside the valve. Once it was cleaned out, my hot water pressure was restored and everything functions properly.

[Larry_M]

Update. After actually turning on the heating element (electric) the water did indeed warm up. When I first turn on a faucet the water comes out hot but within about 30 seconds it drops in temperature to warm. The water pressure remains about half of the cold water, however, regardless of temperature. Since we only live about 80 miles from Jackson Center, I've scheduled an appointment to replace the mixing valve while it's still under warranty. The service tech made it sound harder to replace the valve than I was reading on the forums?

I'm just not sure how to prevent something like this in the future. We've always been careful about using a water filter. Others have mentioned water softeners. Do those seem to help? I've also purchased a cleaning wand to hose out the inside of the water heater.

On a side note, they're backed up until the middle of July for service work.

Thanks for all the tips and suggestions!

[DCPAS]

Originally Posted by Larry_M

Update. After actually turning on the heating element (electric) the water did indeed warm up. When I first turn on a faucet the water comes out hot but within about 30 seconds it drops in temperature to warm. The water pressure remains about half of the cold water, however, regardless of temperature. Since we only live about 80 miles from Jackson Center, I've scheduled an appointment to replace the mixing valve while it's still under warranty. The service tech made it sound harder to replace the valve than I was reading on the forums?

I'm just not sure how to prevent something like this in the future. We've always been careful about using a water filter. Others have mentioned water softeners. Do those seem to help? I've also purchased a cleaning wand to hose out the inside of the water heater.

On a side note, they're backed up until the middle of July for service work.

Thanks for all the tips and suggestions!

My theory is that mine clogged when I used air pressure to winterize. I plan to close the inlet valve to the water heater when I winterize in the future.

[JCWDCW]

Is it possible that one of the valves at the HW tank is not fully open?
JCW

[majorairhead]

Originally Posted by Larry_M

Update. After actually turning on the heating element (electric) the water did indeed warm up. When I first turn on a faucet the water comes out hot but within about 30 seconds it drops in temperature to warm. The water pressure remains about half of the cold water, however, regardless of temperature. Since we only live about 80 miles from Jackson Center, I've scheduled an appointment to replace the mixing valve while it's still under warranty. The service tech made it sound harder to replace the valve than I was reading on the forums?

I'm just not sure how to prevent something like this in the future. We've always been careful about using a water filter. Others have mentioned water softeners. Do those seem to help? I've also purchased a cleaning wand to hose out the inside of the water heater.

On a side note, they're backed up until the middle of July for service work.

Thanks for all the tips and suggestions!

I hate to beat a dead horse. The symptoms you describe are exactly what we faced two weeks ago in Stone Mountain Georgia at the campground there. We were de-winterizing and had what sounds like an identical issue.

Hot water briefly, then warm, low pressure.

Not until I fiddled with all the faucets, outside shower, toilet flush, low point drains etc. while both pump and city water were hooked up did I finally get all the air out of the lines and the hot water began flowing well, and hot

I'll bow out, stage right.

[Wazbro]

Originally Posted by JCWDCW

Is it possible that one of the valves at the HW tank is not fully open?
JCW

Doubt it. the newer trailers with the mixing valve use 1 valve and the mixing valve to bypass the water heater (yes that means always using the mixing valve).

[Dennis C]

Originally Posted by Larry_M

Since we only live about 80 miles from Jackson Center, I've scheduled an appointment to replace the mixing valve while it's still under warranty. The service tech made it sound harder to replace the valve than I was reading on the forums?

I removed, cleaned and reinstalled my mixing valve in a campground for the first time last week. The only tools needed were a pipe wrench and some plumber’s tape. Removal took about 2 minutes. Cleaning and soaking took about an hour, and reinstallation took about 2 minutes. The hardest part of the whole endeavor was assembling the right tools, including some for draining the water heater. I had to buy the 10” pipe wrench for the mixing valve and a 15/16” shallow socket for the water heater drain plug at a local Home Depot store.

[Domo]

Running up my 2020 16RB Caravel after winter. I followed a winterizing procedure detailed here.

https://www.youtube.com/watch?v=S633uF9xL_4

. It didn't mention switching the winterizing valve on the cold input to the heater; frankly, I didn't know that existed until yesterday.

I am now experiencing the same problem as the OP called out in this thread.

I swapped out the heater mixer valve (wow, expensive), but that hasn't improved things. The heater seems to start up correctly and heat the water in the tank; I get very hot water good pressure out of the external blue relief valve (the one with the ring pull under the outside cover). I have also tried turning on all of the faucets to clear and air blocks. However, it doesn't provide hot water at pressure to the shower or the sink.

We are leaving on a 3 week voyage thru UT in a few days and I am going to have a very grumpy wife if I don't figure this out.

Is there anything else that you can think of doing before checking it into the dealer to fix?

[JCWDCW]

Cold water always flows. There is no shut off for cold water at the valve

[Too tall]

Originally Posted by Domo

Running up my 2020 16RB Caravel after winter. I followed a winterizing procedure detailed here.

. It didn't mention switching the winterizing valve on the cold input to the heater; frankly, I didn't know that existed until yesterday.

I am now experiencing the same problem as the OP called out in this thread.

I swapped out the heater mixer valve (wow, expensive), but that hasn't improved things. The heater seems to start up correctly and heat the water in the tank; I get very hot water good pressure out of the external blue relief valve (the one with the ring pull under the outside cover). I have also tried turning on all of the faucets to clear and air blocks. However, it doesn't provide hot water at pressure to the shower or the sink.

We are leaving on a 3 week voyage thru UT in a few days and I am going to have a very grumpy wife if I don't figure this out.

Is there anything else that you can think of doing before checking it into the dealer to fix?

Just in case you have not bleed the low point valves and outside shower please give that a shot. Sometimes just having that air space in the lines is enough to cause these symptoms.