Whale Water Heater

[Amuir47]

Hi,

New to the forum and looking for a bit of advice/assistance.

I had an issue with the Whale pump constantly switching on and off…traced the issue to the drain valve on the water heater leaking so assuming the pressure drop in the tank was causing the pump to kick in. Due to this, overnight I switched off the pump so that it wouldn’t keep coming on.

However, recently my Whale underfloor water heater started tripping the mains. After filling the water heater with cold water, the temperature gets to around 22°C and then trips. I’ve checked out the element (2x750W) and it seems ok however I’m not confident that it is not failing underload. Is the element failing as the heat increases? Possibly a slight crack?

Now, I am not sure if I have caused this issue by keeping the pump turned off without turning the water heater off. I thought that the heating would cut off should the tank be low in pressure/empty? Am I correct in saying this?

I have ordered a new drain valve and element to see if this cures the issue but have also found a few dry joints/blow marks on the main PCB (see attached photos) which may need replaced also. Could the issue be that the control board is faulty?

Any suggestions as to the root cause/confirmation of the proper workings of the water heater would be much appreciated.

Thanks,

Andy

 

[Mel]

Hi. Welcome to the forum. I can’t help but I am sure someone on here will have some ideas. The only thing that I do know is that Whale do have good technical support and do sometimes add a comment on this forum. Worth an email if you get no on joy here.
Good luck
Mel

 

[ProfJohnL]

Unfortunately the pictures you have supplied are to blurred to really tell if its got poor solder joints, but I do wonder if some of the PCB has been flooded as part seems to discoloured.

Electrical appliances especially heaters that stop working consistently after a few minuets is often due to something expanding and exposing or breaking a fractur point in an element, but when you say the mains eclectic is tripping, exactly which trips (RCD or MCB) is tripping?

Most caravan water heaters will have some form of over heating protection, which will cut power to the elements. Sometimes its a self resetting switch some times it needs human intervention, and some times its a thermal fuse that will need to be replaced, once the reason for the overheat has been established. Over heating can be caused by insufficient water volume in the tank.

Most water heaters do have a excess pressure relief system which will dump some water to reduce the pressure.

Realistically I suspect you need to have the hetare checked and repaired by a qualified fitter.

 

[Amuir47]

Unfortunately the pictures you have supplied are to blurred to really tell if its got poor solder joints, but I do wonder if some of the PCB has been flooded as part seems to discoloured.

Electrical appliances especially heaters that stop working consistently after a few minuets is often due to something expanding and exposing or breaking a fractur point in an element, but when you say the mains eclectic is tripping, exactly which trips (RCD or MCB) is tripping?

Most caravan water heaters will have some form of over heating protection, which will cut power to the elements. Sometimes its a self resetting switch some times it needs human intervention, and some times its a thermal fuse that will need to be replaced, once the reason for the overheat has been established. Over heating can be caused by insufficient water volume in the tank.

Most water heaters do have a excess pressure relief system which will dump some water to reduce the pressure.

Realistically I suspect you need to have the hetare checked and repaired by a qualified fitter.

My initial thoughts were that the board had suffered some sort of flooding.

The main RCD in the house/or whilst it wason site was tripping.

 

[trevormonty]

Element may have been damaged by low water in cylinder. As it heats up the insulation could be breaking down shorting through water causing RCD to trip. You said it was 2x750W element, try running them individually. Fault is likely to be in one not both.

 

[Amuir47]

Element may have been damaged by low water in cylinder. As it heats up the insulation could be breaking down shorting through water causing RCD to trip. You said it was 2x750W element, try running them individually. Fault is likely to be in one not both.

This was the route I was thinking. Potentially a crack in the element now and it expands as it is heating up and shorting due to water ingress.

I tried running on 3.3A and 6.5A settings but trips on both occasions. Possibly the element linked to 3.3A that is faulty. I could have swapped the +V line for the elements and tried again to prove this but I’ve already stripped the element out to inspect it. I’m going to change the element and use the original PCB (after cleaning up the solder joints) and see what happens. Failing that then I will change the PCB for new.

Just find it strange that (if this is the cause) the water heater allows heating with a low level of water. I think there is a case for an inductive level switch of some sort that doesn’t allow the heater to operate if the water level drops below the level of the element.

 

[trevormonty]

This was the route I was thinking. Potentially a crack in the element now and it expands as it is heating up and shorting due to water ingress.

I tried running on 3.3A and 6.5A settings but trips on both occasions. Possibly the element linked to 3.3A that is faulty. I could have swapped the +V line for the elements and tried again to prove this but I’ve already stripped the element out to inspect it. I’m going to change the element and use the original PCB (after cleaning up the solder joints) and see what happens. Failing that then I will change the PCB for new.

Just find it strange that (if this is the cause) the water heater allows heating with a low level of water. I think there is a case for an inductive level switch of some sort that doesn’t allow the heater to operate if the water level drops below the level of the element.

Lot of extra cost for what if situation that rarely happens. More likely the extra protection circuit will fail and result in no HW.

 

[ProfJohnL]

....

Just find it strange that (if this is the cause) the water heater allows heating with a low level of water. I think there is a case for an inductive level switch of some sort that doesn’t allow the heater to operate if the water level drops below the level of the element.

Most touring caravan storage water heaters utiles the displacement method of gettin hot water out or in simpler terms you have to push cold water in at the bottom to push the hottest water out at the top.

It is usually the responsibility of the owner to ensure the drain valves or plugs are closed before using the heater. The fact the water surrounds the elements normally regulates the temperature of the elements. But as a back stop there is usually an over temperature device (thermostatic switch or thermal fuse) which is fitted to the elements plate and if its not submerged to keep it cool then the temperature will climb and trip the device.

Unfortunately elements can wear out and as you have described crack with age or if they have cycled above their normal water heating temperature if for example the heater hasn't been properly filled.

Obviously I cannot remotely tell what has actually happened, but from my experience of other makes of heater I can say the above is very typical.