No water out hot side

[Dangboston]

I have a pressure system that gives me water out the cold water tap.
I replaced the pressure pump because I was not getting anything out either hot or cold side of tap.
I now get water out the cold side in galley cockpit and head, but nothing out the hot water side anywhere.
I am new to boating and could use help with this. I don’t know how to clear an air lock in pressure water system. Could this be the problem? What other issues could it be and how do I fix it?

[James S]

Welcome to Cruisers Forum Dangboston..
Is this a new issue with the hot water supply?
Have you left the hot water valves open sufficient time.. when you do can you hear the pump running?
have you looked under the sink to see if there is a connection to the hot side?

[a64pilot]

I changed got to hot, I assume it was what you meant?

First did this just happen or has it always been that way?

[CaptTom]

Could the water heater be empty? It can take a while to fill up before water starts coming out the taps. If you hold your palm over the tap for a few seconds, then release it, you might hear and feel the air escaping under a bit of pressure.

In the end you really should figure out where everything in your potable water system is connected, where each pipe goes and what each fitting does. Until then we're all just guessing.

[ramblinrod]

Originally Posted by Dangboston

I have a pressure system that gives me water out the cold water tap.
I replaced the pressure pump because I was not getting anything out either hot or cold side of tap.
I now get water out the cold side in galley cockpit and head, but nothing out the hot water side anywhere.
I am new to boating and could use help with this. I don’t know how to clear an air lock in pressure water system. Could this be the problem? What other issues could it be and how do I fix it?

First things first.


DO NOT TURN THE WATER HEATER SWITCH ON UNTIL YOU VERIFY IT IS FULL OF WATER. (Doing so could trip the high temp reset switrch or burn out the element.)

Is this a new to you boat?

1. Does it physically have a water heater? (Some fail and are removed.)

2. Is the water heater connected to the faucet? (It could have failed and been capped off.)

3. Is there a valve in the hot water plumbing circuit before the faucet that is closed?

4. Have you left a hot water faucet open long enough (with the pressure water pump running) for the all of the air to be expelled out of the water heater, before water can be delivered to the tap?

[FabioC]

Also, some water heaters have a valve on the intake from the tank (mine has), or the valve could be on the pipe out of the tank, which may be shut (check that if present, the water heater will eventually fry if used without water).

[Dave22q]

Start by ruling out a leak in the hot water system. With the water tank full do you see a loss of pressure after running cold water? Other symptoms; unxpected water in the bilge, need to frequently refill fresh water tank and hissing when you first open a hot tap.
After ruling out a leak about the only thing that can cause zero hot water flow is a blockage the lines to or from the water heater. If the line out is cold after the heater has been on a while blockage of the intake line is almost crtainly the issue. There will be a "T" connecting pump outflow with the cold and hot water lines. The other end of the hot line is the tank feed. Start there. After disconnecting at the tank, if you get water with the pump on, the problem is a block in the line or the T. Then either clear the blockage or replace the T. If you do get flow you have two problems; failure to heat and blockage in the downstream lines. When you disconnect the heater outlet a flow of cold water will confirm both issues. The odds on this are slim. Bottom line when a heater fails you get cold water, getting no water means leaks or a blockage.

[bobfromcanada]

Most pressure systems have a check-valve on the input to the hot water tank to stop hot water from migrating into the cold water side. If that valve has stuck, that could explain the symptoms you have noted.

[Cadence]

I'd go with what Capt Tom said. Chances are your water heater was drained. Replacing the water can be slow. You may want to open all of your hot water taps at the same time. If by some fluke the WH is above the taps disconnect it output connection to bleed air.

[Taswildlife]

Hi
Just wondering if, when you bought boat both the hot and cold water were working and whether this problem developed after the pressure pump went down? or if it was like this when you bought it?
Like some of the other contributors have mentioned the first thing to work out is.. Is there cold water getting to the cold water inlet into your hot water tank? Once you have discovered that then it's a matter of filling (priming) the tank and hot water lines. This can only happen if the air is allowed to escape from the top of the tank via the hot tap, overflow or pressure relief valve (on some) as the cold water fills the water heater tank from the bottom cold water inlet. The usual suspects here would be. A valve is turned off, there is a blockage or an airlock. You could identify a leak as the pressure pump would continue to work when all the taps are turned off. A blockage could be identified by working back to the pump from the H/W tank and checking all connections (or the other way). I'm in Australia and some of the H/W tanks we have here are configured differently with the hot water to tap being drawn through a heat exchange coil immersed in a static heated body of water in the tank so it might be worth checking with the H/W tanks manufacturer to see if there are any tricks. If you are in a marina it might be worth back or forward flushing with a garden hose from the mains to dislodge a block or expel air with the greater pressure.

[GordMay]

Greetings and welcome aboard the CF, Dangboston.

[Dangboston]

Thanks, I will start at cold fill and work forward as you suggest.

[US1Fountain]

If the boat has been winterized before you bought it, possibly the WH bypass (if equiped) is still in the bypass mode and/or a valve is closed at WH. I would think you have a 5 gal water heater. shouldnt take more than a 30 sec-1min to fill, and then you would see air/water spitting out the faucet with the hot side opened if it was just empty till it filled up. Just need to open a hot water faucet at a sink to let the air out of the water heater once you determined no valves are closed for normal use.