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[Kosrug]

Evening All,

I'm a complete beginner with DIY so please bear with me. I have recently had a problem with the cylinder (HERCULES Direct Copper Cylinder) that heats the water of my flat.

There is a night switch and a day switch that's used to heat the water, the night switch is working fine but the day switch triggers the main trip switch so now do not have any hot water during the day. :(

I've tried looking into what could be the problem so have taken the cover off (where the wires from the main switch go to the cylinder) and nothing looks corroded or wires loose, apart from a gage (got the name SATCHWELL and looks like a timer or a temperature gage with no's 10 to 80 on it) that is loose and can move without any problems. Is this supposed to be like this?

Any help would be greatly appreciated and who should I call if it isn't a job for a novice?

Thanks! :D

[stevenc1603]

If I remember this correctly the cylinder will have 2 immersion heaters in it.

I think the upper one is the day one as it only heats the upper portion of the water nearest the outlet.

The night one either turns on the bottom one on its own or turns on both, I can't remember which.

I would guess that perhaps the bottom heating element has gone but you would need to get it tested to be sure.

[marrtin]

Well, it's a bit of a guess without checking further, but you will probably find the immersion has corroded inside the tank which is causing the trip to activate.

Assuming this is the case, it needs replacing. They can be tricky things to remove, as they need a special box spanner and a careful hand so as not to damage the thin copper tank. You need to be familiar with 230 volt electrics too.

A plummer would be your best course of action.

[djguest.fsnet.co.uk]

hi if its the day switch thats tripping the trip, it will be your top element that needs replacing.this is providing that electrics to it are ok.

[Kosrug]

Thanks very much for all your help! Gives me an idea of what I can look into before calling out the EXPENSIVE plumbers! :P

[db60]

Hi Kosrug,
I had a similar problem where the bottom heater had failed and the top heater worked. That meant no heating was available during the off peak hours. Yesterday I completed the job after having an accident by flooding the airing cupboard and hall in attempting to drain the cylinder from the wrong drain cock.

The task is not too difficult but time consuming.
TURN OFF THE ELETRICAL POWER TO THE HEATERS.
First turn off the supply to the cold tank and drained the tank. ( I am not sure it was necessary as there was a stop cock from the cold tank to the hot water cylinder which I could have turned off and it have been sufficient)
Then using a box spanner for immersion heaters ( I found the simple immersion spanner was not very useful and had to return it.) just free the immersion heater. You have to give it a sharp tap with a hammer before you you can give it a quarter turn. At this stage dont undo it more!!

Then find the drain cock on the cold feed to the cylinder. It will be on the pipe that enters the cylinder near the bottom. ( The pipe at the top of the cylinder supplies hot water to your flat.) Attach a length of hose pipe to the dran cock with the other end out of the flat if possible or in a bucket if not. Open the drain cock and start draining. This may take an hour or more. Depending on how low the drain cock is situated you will find that when you think you have drained the tank there is still quite a lot of water left. This I drained by slowly undoing the heater and letting the water out and catching it in a saucepan. You will have to do this several times as there will be several saucepans worth of water left.

Undo the electrical connections and unscrew the heaters and withdraw them. You may have difficulty in withdrawing the heater as the end may have splayed out.

Screw in the new heaters and make sure you use jointing compound like Plumbers Mait. Make the electrical connections.

Turn on the water to the cold tank and turn on the electrical power.

I found that I had a lot of water seeping down the hose pipe at the drain cock end. Fitting a jubliee clip would solve that. I also had a lot of water splashing when i was draining the last bit through the heater boss. Put down lots of old towels!!

Good Luck.

[Kosrug]

Hi,

Thanks for all your help and advice!

Now this is what has been done so far, so the problem was the element that has now been changed by a plumber think it would've been too much to do the job myself, but after watching them do it it didn't seem too difficult. Now the bottom element does not seem to power up, it is not tripping the switch but have changed the bottom and top element for new ones and the bottom one is still not working.

Could you let me know what you think could be the problem?

[marrtin]

Have you checked to make sure the bottom element is not on an Economy 7 tarriff, and only heating between 1am and 8am?

[Kosrug]

Yep it is an economy 7 but that is the problem it used to come on after 12 midnight but now doesn't heat up at all.

[marrtin]

All that can be done now is to test the electrical circuit to see if the element is faulty or the wiring has been disturbed and now not working.