Halstead Finest Platinum...again!!

[Gasguru]

The hall effect magnet and the switch are in two parts, so whats so difficult to understand " the hall effect or the dhw switch" ?

because there's no such thing as a hall effect magnet. There's a plain old magnet and the separate hall effect sensor in the plastic housing that clips on.

This bit contains the magnet assembly that shuttles on a DHW demand....

http://www.boilerparts.co.uk/Uploads/HALSTEAD/500640.jpg

and this bit contains the hall sensor circuitry....

http://www.boilerparts.co.uk/Uploads/HALSTEAD/500641.jpg

 

[picasso]

Yea sorry for making a mistake

 

[disponded]

I removed the pump and heat exchanger yesterday and they were both clear and not blocked. I then realised that it was the pump that was failing and was intermittently working and sometimes not running at full strength.
I picked up a new pump head from the wholesalers today and fitted it this evening. Heating and hot water now running perfectly. In fact I would say that the radiators have never been so hot as long as we've been in this house.
Now to get my gas engineer round next week, when he's back from hols, to give it a service.
Thanks to you all for the help and advice.