Dual Immersion Off Peak Heating No Longer Comes On

[shazchip]

Hello,

Can somebody help me with a problem please?

I have noticed that my immersion heater no longer heats up overnight.  I had the element(s) replaced not so long ago so thought it was strange, and did a little investigation.

On the control panel I can change the current time, so I changed it artifically to night time (cycled through all hours from midnight until early morning), expecting that the light for the off peak heating would come on.  But it didn't.  So I think the problem is with the timer and not the element.

I have no idea where the timer is, also don't know if I need an electrician for this or someone else (it was a plumber who changed the immersion element), or if this is actually something to do with the electricity company (I think I read somewhere before that they are the ones who 'send a signal' at night if you're on an economy 7 tariff to turn on the off peak heating) ???

Any advice on which direction to go for help would be amazing!!

Thanks in advance.

 

[ProDave]

Tell me more about this timer you were adjusting.  I'm a bit confused by the fact you were adjusting a timer, but don't know where the timer is.

I assume your tank has two immersion heaters.  If so have a look at the bottom one.

Follow the cable from it, it should come from a switch on the wall close to the tank. Turn that switch off, then undo the nut that holds the cover on the bottom heater and have a look inside. You should see the thermostat, and look VERY carefully there will be a tiny little reset button, often just a TINY hole into which you insert something small to press a tiny little button.

If when you press it, the reset button goes click, then that was the cause of the problem.  Before putting the cover back on, turn the thermostat dial down a little bit to try and prevent the trip tripping again.

 

[shazchip]

Hi ProDave,

Thanks very much for the response.

The time I was adjusting was just the clock on the control panel on the wall. I guess that the internal timer, wherever/whatever that is, runs off this... e.g. if clock_time==off_peak_switch_on_time, then the off peak heater is triggered on??  So in the past when I've changed the clock so that the control panel thinks it's 4am, and I see that the off peak timer is triggered, and when I change the clock back to 10am, it turns off again.

I followed the cable to the wall, it went into the control panel, so I turned that to 'Off', and I also turned off the breaker switch for the water heater, just to be on the safe side.  I took the cover off the bottom heater, it's in a really awkward position in the cupboard so I couldn't get my head round to look at it face on unfortunately. I couldn't see anything that looked like a reset button.  There were two largeish holes labelled A and B but from the looks of a tiny circuit diagram on it it looked like they may just be probe points to test voltage/resistance across two wires? Since it also says 'Cotherm'.  I also couldn't really tell what was the thermostat, there was a little red dial numbered 1-5, and it was set to 4.  Is that it (for the purposes of turning it down..)?

Anyway after having had a look, I thought, let me try and turn it back on again at the wall and see if that's somehow reset it.  And it has! When I now change the clock to say 3am, the off peak turns itself on   Som thankyou very much for your help.  Anything you think I should know / anything I did wrong??


Thanks,
Shazchip.
 

 

[ProDave]

Glad it's sorted. Sounds like a complicated timer that wanted to be re booted.

With those cotherm units the big round thing you see is the thermostat that plugs onto the heater element terminals.

I thought if it had been replaced recently it would be one that has the new reset button, the older ones don't.

 

[shazchip]

Cool, thanks again!

Cool, thanks again!