Question. Signal for hot water not getting through

Whin · Jun 22, 2019

Hi all,
 
After boosting the hot water for probably too long on our pulsacoil thermal storage, the circuit breaker was tripped and I saw that the timer unit had melted through.
 
I got a replacement unit and have installed it and flicked the circuit breaker switch back on. The water seems to be heating up because the boiler unit becomes warm - but water out of the hot tap stays cool. I think there's a communication issue somewhere - as if the signal for hot water isn't coming through.
 
Any guidance much appreciated. I'll be getting an electrician this week I think.
 
The timer unit is a TRTM7
 
Thanks 

baldelectrician · Jun 22, 2019

You need someone with a meter to check it
It could be the new timer, wiring, connections, thermostats or the element

A decent meter is needed to check this.

littlespark · Jun 22, 2019

The photos there look like a standard e7 immersion controller. Is that what you have?
Show photo of front of unit.
Is this your old controller or the new one?
Might just be a shadow but it looks like terminals 4 and 3 are dark through overheating.
Also the link between 4 and 5 doesn’t need to be that long.

davesparks · Jun 22, 2019

Did you replace the back box for the timer or just plug the new one in to the existing back box?

Pulsacoils can be a nightmare at times, pop the front cover off of it and see if the LED on the control pcb is flashing. Different numbers of flashes are used to indicate possible faults or that the pcb is working correctly, no flashing indicates no power to the control pcb or a dead pcb.

Be aware there are 3 mains supplies in to a pulsacoil, one to each immersion heater and a third to power the control pcb.

Also check that you haven't switched off the control power by accident when isolating the immersion heater supply to replace the timeswitch.

Whin · Jun 22, 2019

davesparks said:
Did you replace the back box for the timer or just plug the new one in to the existing back box?

Pulsacoils can be a nightmare at times, pop the front cover off of it and see if the LED on the control pcb is flashing. Different numbers of flashes are used to indicate possible faults or that the pcb is working correctly, no flashing indicates no power to the control pcb or a dead pcb.

Be aware there are 3 mains supplies in to a pulsacoil, one to each immersion heater and a third to power the control pcb.

Also check that you haven't switched off the control power by accident when isolating the immersion heater supply to replace the timeswitch.

Thanks for the reply. I replaced the entire timer unit and made sure to match the wiring. Some pictures below. I'll take the front face off the main unit tomorrow

[ElectriciansForums.net] Question. Signal for hot water not getting through

Whin · Jun 26, 2019

davesparks said:
Did you replace the back box for the timer or just plug the new one in to the existing back box?

Pulsacoils can be a nightmare at times, pop the front cover off of it and see if the LED on the control pcb is flashing. Different numbers of flashes are used to indicate possible faults or that the pcb is working correctly, no flashing indicates no power to the control pcb or a dead pcb.

Be aware there are 3 mains supplies in to a pulsacoil, one to each immersion heater and a third to power the control pcb.

Also check that you haven't switched off the control power by accident when isolating the immersion heater supply to replace the timeswitch.

Hi Dave,
While waiting for a professional to come look at this I've removed the front cover and seen the PCB is flashing green. Is there a reset or something that I need to flick?

Thanks

davesparks · Jun 26, 2019

Whin said:
Hi Dave,
While waiting for a professional to come look at this I've removed the front cover and seen the PCB is flashing green. Is there a reset or something that I need to flick?

Thanks

As I said before, different numbers or sequences of flashing are used to indicate possible faults or correct operation.
There is nothing to flick, but check the sequence of flashes against the chart in the service manual to see if it is operating correctly.