Unstable, sometimes completely cold temperature

Hi,

Since moving in 18 months ago we have had constant temperature problems with the Pulsacoil 2000. It used to be hot,cold,hot,cold etc.,no red lights on the boiler. Now, there are still no red lights, but to try and get the mixer shower taps to work the hot tap has to be opened very slowly and the cold tap introduced only when the hot water has stopped squealing. By the time the squealing has stopped the hot water flow is almost a trickle and it can take upto 5 minutes of fine tuning to get a reasonable flow using the hot and cold taps. More and more often the water seems okay for a few minutes and then suddenly the hot water stops completely and you are left with a cold shower. If the taps are turned off again for 10-15 minutes the hot water works again.
I imagine this is something to do with the heat sensors? Ideally, we would like to fix it ourselves so any advice and tips would be great. Thanks

Hi DEBBIE.P

Well yes the first thing I would do is to change the DHW heat sensor. The hot/cold/hot/cold is a classic indicacator of it failing. If the problem persists after changing it I'dchange the other sensor too and check the heat exchanger for scale contaminination.

Not sure what the squealing noise you mention is though. I doubt is is anyting to do with the Pulsacoil but it could be related.

Fix one thing at a time though. Do the DHW sensor first!

Cheers, Mike

It could be the sensor, pump or PCB which are causing these problems. Also check the water level in your header tank. If you are not sure how to, request a free self check Pulsacoil mini guide which will explain this and go over other things you can do. You can request this guide via this link: Gledhill Pulsacoil 2000 Repair