Halstead Gold combi boiler locking out

[davidstanley]

ive got a halstead gold combi boiler that keeps locking out when the hot water is turn on above anything more than a dribble. Its only occured for the last couple of weeks. Under lock out the heating then fails to work.

The water pressure in the system is fine and the boiler has been in good working condition.

Any idea's what may have gone wrong.

the water pressure into the house remains good.

many thanks for your help
dave

 

[ChrisR]

Does the CH work if you reset and don't turn the HW on?

Before it packed up, did the HW go hot - cold - hot - cold??

I suspect the secondary heat exchanger is blocked solid.

 

[scatmanjohn]

If it only does it when you have the heating on,

Then:


That fault usually happens because the boiler flow switch dips as the diverter is moving from central heating to hw.

If that switch drops out it will instantly lock out.

If you drop the front down you can see the switch on top of a brass housing, a small pin moves up when the pump runs.

Put the CH on, watch the pin whilst getting someone to run a hot tap.

Does the pin dip down?

 

[davidstanley]

the boiler locks out regardless of if the heating is on.

I'll have a look again today.

the CW works when i reset the boiler or when the Hw is off..

What do you think of these old halstead boilers, am i better to cut my losses and replace with a worcester CDI or something. We have always had terrible problems with flow rate from the boiler.

 

[ChrisR]

They have their "issues" but you'd have had the same flowrate with a 28Cdi. Nothing at all special about a Worcs Cdi in fact, highly overrated.

How soon after turning the tap on does it lock out>?

 

[davidstanley]

yes it does' near straight away.

what about the 30cdi, or could you recommend another?