Immersion heater not working.

[Zayna]

It's not the fuse or the reset button. Water heats fine via running the engine. Before husband drains the tank to fit a new element, could it be anything else?

[luggsy]

Firstly DONT drain the tank until you undo the thermostat as it will probably be seized in

[Onewheeler]

Failed thermostat? No electricity reaching it?

[Chewbacka]

1 hour ago, Zayna said:

It's not the fuse or the reset button. Water heats fine via running the engine. Before husband drains the tank to fit a new element, could it be anything else?

Either power is not getting to the heating element - for example - fuse blown, switched off, duff connection (boats vibrate a lot and simple screws clamping the twisted end of a wire can often come loose), thermostat stuck open,

 

or power is available but the element has failed.  The best way to check is with a voltmeter, but I guess if you were confident/safe in using one of those you would have done that already.  Anybody near by that could do that for you?

[Nightwatch]

Hello Miss Zayna, haven't seen on here for ages. Trust you are well. 

 

Can't help with your issue, so a pointless post from me it is then.

[Zayna]

44 minutes ago, Nightwatch said:

Hello Miss Zayna, haven't seen on here for ages. Trust you are well. 

 

Can't help with your issue, so a pointless post from me it is then.

Hello! All good thanks, hope you're well too ?

[bizzard]

If your in a hard and limescaley water area the element has probably coated with it, overheated and blown. Check the power to it with multimeter set to AC mains. Switch the pump off and release the pressure by cracking open a tap before removing the element.

[MtB]

Pointless doing the work of changing the element on a guess. Diagnose the fault properly THEN fix the real fault.

 

1) Get a multimeter

2) Use it to measure for 240Vac on the lead into the heater element.

3) If no voltage, find out why

4) If voltage present, turn it OFF

5) Set multimeter to Ohms

6) Put prongy things on the two heater element terminals. You are looking for 20 Ohms for a 3kW heater or 60 Ohms for a 1kW heater, approx.

7) If you have 20/60 Ohms the element is good and doesn't need changing

8 ) Measure the resistance across the two terminals on the thermostat. It will probably be open circuit

9) Find the tiny little overheat protection reset button on the thermostat and press it in

10) If no reset button fit new thermostat

 

Hope that helps...

 

[Zayna]

Thank you all. I will print out all your replies and present them to the committee. ?

[Mac of Cygnet]

4 hours ago, Zayna said:

Thank you all. I will print out all your replies and present them to the committee. ?

 

You don't need all the replies. MTB's is comprehensive, accurate and easy to follow, as expected.

[gbclive]

4 hours ago, Mike the Boilerman said:

Diagnose the fault properly THEN fix the real fault.

Nicely structured Mike?

In a previous life, we used a mnemonic to help with problem solving and decision making - DODAR.

 

D - Diagnose the problem. Time spent on this is rarely wasted.

O - Generate options.

D - Decide on the best option with a bias towards simple.

A - Assign tasks and consider delegating.

R - Review to see if you have solved the problem.

 

It’s not perfect - sometimes a couple of T’s are added?

Threats - consider the threat or risks v benefits.

Time - how urgent is it.

 

And finally apply a good dose of common sense!

[ditchcrawler]

8 hours ago, luggsy said:

Firstly DONT drain the tank until you undo the thermostat as it will probably be seized in

I think you mean element

[Wanderer Vagabond]

Out of curiosity are you on a mooring or continously cruising? The reason that I ask is that my immersion failed about 2 years ago and since I'm not going to run it unless on electric hook-up I have never missed it. In the last 2 years there has been just one occasion when I might have used, but then I am very rarely on an electric hook-up.