Help! Pulsacoil 2000 No Hot Water on Off-peak

Hello,

Can anyone help with the following:

My Pulsacoil 2000 boiler tripped out 3 times and as a result found that the off-peak thermostat was faulty and both thermostats were replaced.

Following this the hot water worked fine on both on-peak and off-peak settings. However, after one batch of 'off-peak' electricity the bottom thermostat then tripped out. Checked wiring was all ok and reset the bottom stat. Again, all worked properly and hot water on both on-peak and off-peak settings.
But the same thing happened...after one batch of off-peak electricity the bottom stat has tripped out and no Hot water on off-peak electricity suppl.
There is no problem with the on-peak stat - can get hot water using this.

Has anyone any ideas what the problem could be?

Thank you

Thank you

Forgot to mention that red light is flashing twice on PSC.

HI

The symptoms that you have described are typical of the off-peak elementbeing contaminated with scale deposits. These deposits are in the form of a thick sludge that envelops the element and prevents the heat from escaping, resulting in the overheat section of the thermostat tripping out.

I'm afraid the only solution to your problem is to have the element replaced. In our experience, if the off-peak element is affected, the peak element is usually affected too and it would be wise to deal with both at the same time whilst the unit is drained.

We cover the Midlands and would be happy to help, but I would reccommend that you use a Gledhill specialist wherever you are.

Hi David,
Thanks for your reply and advise on this.

An update to this - we switched the wiring from off-peak supply to on-peak supply, to ascertain if this was definitely the problem.
So far after 3 lots of on'peak electricity (now using the bottom thermostat) it has not tripped out!

Not sure if this would be usual ...and the tripping out of bottom thermostat when wired to the off-peak supply, might be the longer duration of time that it is being suppled with
electricity?
Or could this point to another problem.

Advice would be appreciated.
Am in London ...not the Midlands!

Thankyou

jh7 wrote:Hi David,
Thanks for your reply and advise on this.

An update to this - we switched the wiring from off-peak supply to on-peak supply, to ascertain if this was definitely the problem.
So far after 3 lots of on'peak electricity (now using the bottom thermostat) it has not tripped out!

Not sure if this would be usual ...and the tripping out of bottom thermostat when wired to the off-peak supply, might be the longer duration of time that it is being suppled with
electricity?
Or could this point to another problem.

Advice would be appreciated.
Am in London ...not the Midlands!

Thankyou

as stated from the midlands, you need 1 new immersion heater, the off peak one is scaled /clocked up, but as recommended, course this needed a drain down, fit both new, peak and off peak.
by the way, i am working now and again in SW London and if you need help get on my website
Mario at Mario's Boiler Service ( www.marios-boiler-service.co.uk)

Leave the bottom element on for a longer duration and see if this problem persists. It is a strange scenario but I would have to agree with Mario, it sound like sludge. When you switched the supply over, did you switch the top and bottom thermostat around? If you did, the thermostat maybe the problem. Also are you using the correct thermostat and not a standard one that reaches 65oC? These thermostats should reach 73oC.

The link below will take you to a page with a picture of the thermostat, see if they match.
Gledhill Pulsacoil 2000 Spares

XB081 is the part it should look like