The hot water flow in my 2000 410...

[PolarExpress]

The hot water flow in my 2000 410 Sundancer is really slow, ever since I bought the boat 2 years ago.  I've just replaced a leaking relief valve on the hot water tank and finally got the tank up to proper temperature, but hot water still comes out of any of the faucets as only a trickle.  The cold water flows just fine, however.  Anyone else with that problem?  Any suggestions?

[wingless]

There is an obstruction that must be located and corrected.

Start at the water heater and move through the system.

Open the water heater drain valve to verify good flow. Open the water heater safety valve to verify good flow.

The fresh water system has the Watts Series 10 and 35 PEX plumbing and fittings. They may be disassembled / reused / reassembled to reconfigure the system.

If the hot water tank output is removed from supplying the boat to instead going to a tube pointed at a bucket, then the flow can be verified.

There is a safety blend valve on the hot water output, that mixes in cold water to reduce the risk of scalding. It is possible that the moving parts in that valve have failed w/ the result of decreased flow.


http://media.wattswater.com/PL-Quickconnect.pdf

[PolarExpress]

Thanks, a logical approach. I'll try it and see what happens. It'll be a few days before I can get back to the boat, though.

[SeaMax]

First I assume you have determined that it is hot water outlets, not just one. And that your cold water flow is correct. That being said, look at the discharge side of your water heater - you will find a tempering valve. That valve is designed to mix some cold water with the hot so that the tap water cannot be hot enough to scald someone. The valve will turn due to vibration. There will be an arrow on top of the valve showing hot and cold directions. Turn the valve towards the hot arrow to allow more hot water flow. I have mine set as far as it will go and if I ever replace my water heater that valve will not be reinstalled.

[HUMPH]

I had a similar problem and found calcium deposits in the angled fittings under the sinks. I simply removed the hose from the fitting and extracted these chunks of calcium deposit and now have much better flow. I later used CLR in my water tank and flushed the entire system, left it in the system for a day then flushed with fresh water. It takes time but helped break up deposits. Make sure if you do this to take the aerators off of the faucets so they don't stop deposits from coming out.

[PolarExpress]

Thanks, I will try all those suggestions as I check through the system. I'll be back on the boat next week and try them out.