Water Heater Overheating

[usmm1234]

I don’t use the water heater very often, but the last time I turned it on. It blew the hose off the outlet due to overheating. Soft wall hose and a clamp seem to blow before the pop off pressure valve.
I ordered a new fixed thermostat and breaker from Defender. Very easy to install Without us mounting the heater itself.
It works great now, so I guess It was the thermostat.

 

[Fishtales]

Good find and thanks for sharing!

 

[HMBJack]

Same thing happened to me a while back (2006 330). I thought it was a loose hose clamp. Then it happened again. While fishing, with all the ambient noise, the hose popped off and I didn't hear the pump running endlessly. Filled my bilge and soaked part of my aft berth with 40 gallons of fresh water. Eventually, I heard my high water alarm go off. Ugh...

Thanks to you, I just ordered the T-stat and temp limit switch from Defender.

Thank you for taking the time to post this!!

 

[usmm1234]

based on recommendation from a friend of mine at Grady. I’m going to put a 6 inch piece of heater hose directly on the water heater outlet. Then I will attach it to the plumbing in the boat with a 3/4” nipple and 2 clamps. He said the hose that Grady used was subject to blowing out close to the water heater Due to the heat.

 

[HMBJack]

"I’m going to put a 6 inch piece of heater hose directly on the water heater outlet."

>>>>> I did this and recall it still blew off (2nd time). The very hot water goes well past 6 inches. What worked for me was double hose clamps. The new T-stat and breaker can't hurt anything. My hot water comes out so hot now, I can make tea with it.

 

[usmm1234]

"I’m going to put a 6 inch piece of heater hose directly on the water heater outlet."

>>>>> I did this and recall it still blew off (2nd time). The very hot water goes well past 6 inches. What worked for me was double hose clamps. The new T-stat and breaker can't hurt anything. My hot water comes out so hot now, I can make tea with it.

Thanks for the input. I’ll double clamp it too. Your right though. The water is crazy hot!

 

[usmm1234]

HMBJack was right. My hose still blew off again when I left the water heater on. That’s with a new thermostat and switch. So I added a metal hose to the hot water outlet. I left the breaker on all day. I think the problem is solved! The heat travels about 7 inches down the metal hose When the water is not running. I bought everything at Lowe’s.

 

[DennisG01]

Interesting. When you say "softwall" hose - do you mean something like in that picture? A reinforced vinyl hose? Reason I ask is that my Sea Ray used PEX lines directly off the tank fitting and that was never an issue (nor in any other setup that I know of with PEX). Just wondering if you meant PEX or not? And if it was PEX, I'm curious why it blew off.

 

[usmm1234]

Interesting. When you say "softwall" hose - do you mean something like in that picture? A reinforced vinyl hose? Reason I ask is that my Sea Ray used PEX lines directly off the tank fitting and that was never an issue (nor in any other setup that I know of with PEX). Just wondering if you meant PEX or not? And if it was PEX, I'm curious why it blew off.

Softwall hose what you see coming up thru the hole and clamping onto the hose barb on the stainless hose. My boat is a 2002. That’s all Grady used back then. Pex is good. My company Reps different type of plumbing for boats. We sell pex. It tends to transmit the sound of the pump through out the boat. The push on fittings are also tend to leak after a while.
I will be replumbing my boat next winter With a new plumbing system called PexLock. I’ll post pictures.

 

[usmm1234]

"I’m going to put a 6 inch piece of heater hose directly on the water heater outlet."

>>>>> I did this and recall it still blew off (2nd time). The very hot water goes well past 6 inches. What worked for me was double hose clamps. The new T-stat and breaker can't hurt anything. My hot water comes out so hot now, I can make tea with it.

You were correct. Scroll up and see my latest fix. I think this one will work!

 

[fsc60]

I took the advice and replaced the thermostat and breaker also. When I removed both parts from the water heater I noticed they were both bedded in a white paste. Being a auto mechanic I knew what it was. Its a heat transfer paste. We use it to transfer heat away from electrical components to a heat sink. Makes sense that you would want the temp transferred to the thermostat and breaker. I think without the paste the 2 components might not sense the temp properly and shut the water heater off. I used

Super Lube 98003 Silicone Heat Sink, 3 oz Tube, White​

Bought it on amazon