Plumbing troubleshooting

[RiverRat1]

Newer home around 3 years old. PEX plumbing. Propane on demand hot water heater.

We generally have low water pressure all around (hot and cold) but it's super low hot water pressure in the house.

At hot water heater the pressure is fine also on the output(hot) side. What could cause this and is there an easy fix?

[critter69]

I would check your screens at the facuets first. If In deed it's good leaving the water heater, do you have a filter or any valves after the heater ? Sounds like something is plugged, if again you have good pressure leaving the water heater. Water flow will diminish if the unit can't heat the water quick enough also. But then you would not have good flow leaving the heater. May check your exhaust and intake to make sure nothing is in them. I know we get a real problem with Miller moths blocking them.

[RiverRat1]

I cleaned screens at faucets. Forgot to mention that. And I'm not aware of any filters after the water heater (just one in pumphouse).

Ok, I didn't let it run long enough to see how hot the water gets leaving the unit. But if it starts strong and then peters out (not able to heat fast enough) I'll report back. I'll google how to check exhaust and intake. Thanks

Just checked and it pumps out lots of hot water right after the water heater. Almost like there's a clog in the water line after the heater but before shower (closest thing to heater). That happen when using PEX? How the heck can that be fixed?

[critter69]

If the shower is the first appliance ( hot water) there would be a tee, and branch to the shower and then continue to rest of house. But if the shower and every thing else is weak. I would guess your issue lies between the heater and that first tee.

[Canoe1]

Don’t know if it’s correct to do this, but at camp house, had water issue, used air compressor to blow back the water and after a few times, blew out some sludge like stuff.
of course camp house is old. But maybe there’s something in the line you could blow back out?
just don’t let compressor put out too much pressure

[Greenheadless]

Why you heating already hot water?

[RiverRat1]

Don’t know if it’s correct to do this, but at camp house, had water issue, used air compressor to blow back the water and after a few times, blew out some sludge like stuff.
of course camp house is old. But maybe there’s something in the line you could blow back out?
just don’t let compressor put out too much pressure

Thought about this but not sure how to do it. I for sure do not want to blow air back into water heater. And the other end is faucet in house but blowing air in that way would pressure the entire house.

[tps7742]

Deleted after rereading ops thread again.

[RWB]

Did you check for any screens at the hot water heater. I am trying to rember but it seems like there is a screen on my on demand hot water heater. Also do you have a water softener? If so bi pass it and see it it improves.

[RiverRat1]

No softener. The little filter on the unit is fine. It's still flowing strong after that filter.

[bigmike]

You have some kind of blockage somewhere
can you take the hot water loose at the water heater ?
if so try blowing it out

[bigmike]

By the way imho. Pex sucks out loud !!!

[DedDuk]

Is it 1/2" all the way around ? It should be 3/4" with 1/2" drops to each unit. My guess is they plumbed whole thing in 1/2" and your volume is just not there.

[Greenheadless]

Is it 1/2" all the way around ? It should be 3/4" with 1/2" drops to each unit. My guess is they plumbed whole thing in 1/2" and your volume is just not there.

Mine was plumbed with 1” trunk lines, 3/4” branches, the 1/2” drops.

[AlwaysLate]

Kink in the Pex?