Pulsacoil III problems

I have had a lot of ongoing problems with my Pulsacoil III. I moved into my apartment in November last year, so the Pulsacoil would be 8 years old.

It never really worked great - enough hot water for 2-3 showers, but never enough to run a full bath.

One day, the hot water disappeared completely, so I called a local plumbers to look at it for me, who I have to say, were not particularly knowledgeable about this unit.

They (eventually) fixed it by replacing both upper and lower immersion heaters with new ones, the relay, and a new pump.

It did work fine after that, however the hot water didn't last as long as it used to before, I would be lucky to be able to take 1 shower out of it, then it would go lukewarm.

The problem I had, is that the boiler would heat up water off-peak overnight, but once that was used up the water was stone cold until the next day.

However, a new problem has recently occurred! Even though the boiler pipes are hot to touch, the water in my shower only lasts for a couple of minutes before going cold again. If you turn the shower off, wait another couple of minutes, it will be hot again... for two minutes! And so the cycle continues...

The green lights on the boiler are all fine, and there the water levels are all good too.

Can anyone please advise me? I have spent a small fortune (£700) trying to get this to work so far!!!

Thanks in advance

Hi Howard

Firstly have you checked if the problem is evident at more than just the shower (if it is the Gledhill unit the problem will be evident at every hot water outlet, but if it is just the shower then the shower is your problem not the Gledhill).

If the problem is constant everywhere then your symptoms indicate that there is a problem more than likely with the hot water sensor on the unit, although I have had the thermal mixing valve causing something like this too.

If you're in the Midlands drop me a line and I'll sort out the problem for you.

Regards
Dave Hickey
Midland Boilercare Ltd
service@midlandboilercare.co.uk

Hi Dave,

Thanks for your reply!

The problem occurs at all the water points in the flat (bath, taps, shower), so am pretty sure the Gledhill unit is at fault.

Is the hot water sensor an easy job to replace? If so, I'll order one and replace that and see how it goes.

I'm in East London, sadly probably a little too far away for you in the midlands! I've had two different plumbers come and look at it (about the previous problem) and neither of them knew anything about it!

Regards,

Howard

Hi Howard,

The PHE or DHW sensors may have become faulty. I would recommend switching them over. Also make sure the ware level is correct at the header tank.