Halstead Combi ( not the finest!) gold boiler problem.

[numbersman1]

Would appreciate any advice on a Halstead combi that simply fails to shut off when the desired temperature is reached.

Demand for HOT WATER- Works perfectly! Demand for CH - sometimes refuses to fire up but doesn't go to 'lock out' eventually starts but won't shut off. Thermostat on side of boiler but not in living room.

As a new PCB is £142 i'm worried I could swap it and be no further forward.

Sincerely appreciate any experiences you've had with this boiler (or any other) that I can learn from.

Many thanks
Numbers man

 

[Agile]

You seem to think that you are going to share experiences with other homeowners whose boilers have gone wrong.

On the other hand you might just find a professional on here who could suggest whats possibly wrong but to deal with that you would have to have a meter and be able to do simple resistance measurements.

Tony

 

[numbersman1]

You seem to think that you are going to share experiences with other homeowners whose boilers have gone wrong.

On the other hand you might just find a professional on here who could suggest whats possibly wrong but to deal with that you would have to have a meter and be able to do simple resistance measurements.

Tony

Many thanks for your reply. I do have a multimeter and have no problems in taking resistance measurements having repaired several electronic items in the past. I was simply gathering as much information as I could to help make the diagnosis more predictable and judging by the quality of responses by professionals on this forum, many people have been positively assisted.

 

[Jerzed]

I have this boiler and just had the same problem. Behind the front panel you will see two microswitch units. Check the bottom one. If it has water or condensation inside this will cause it to keep running regardless. Shut off the power, remove the switch assembly and immerse in meths which will dry it out.

Check to see if there is water seeping from the diverter. If there is you may need a new valve, about 150GBP Halstead part number 500601 or Biasi number BI1011503.

Ignore the moaners the Finest is really easy boiler to work on. Fitted a new one and everything is now perfect. Definitely doesn't sound like the PCB.

 

[numbersman1]

I have this boiler and just had the same problem. Behind the front panel you will see two microswitch units. Check the bottom one. If it has water or condensation inside this will cause it to keep running regardless. Shut off the power, remove the switch assembly and immerse in meths which will dry it out.

Check to see if there is water seeping from the diverter. If there is you may need a new valve, about 150GBP Halstead part number 500601 or Biasi number BI1011503.

Ignore the moaners the Finest is really easy boiler to work on. Fitted a new one and everything is now perfect. Definitely doesn't sound like the PCB.

Thank you Jerzed for taking time to reply and clear guidelines on what to do. I've had this boiler for 9 years and its never been any trouble so.. yes... I will ignore the moaners! I think there are far worse boilers out there so I will not criticise Halstead. Again, your interest is appreciated. Thank you

 

[Jerzed]

Alternatively, it is possible to replace the seeping gland in situ. Shut off the water and the heating valves underneath. You can then drain the boiler by connecting a hose to the drain outlet near the back behind the pressure relief valve which is near the front at the bottom rhs. Turning the plastic knob anti-clockwise will drain it.

Once drained it is easy to change the gland. The large nut is 29mm, the small one 13mm.

The service kit is Halstead part number 840503, around 38GBP.

And BTW, I am a householder. ukgalacticathotmaildotcom.

 

[numbersman1]

Alternatively, it is possible to replace the seeping gland in situ. Shut off the water and the heating valves underneath. You can then drain the boiler by connecting a hose to the drain outlet near the back behind the pressure relief valve which is near the front at the bottom rhs. Turning the plastic knob anti-clockwise will drain it.

Once drained it is easy to change the gland. The large nut is 29mm, the small one 13mm.

The service kit is Halstead part number 840503, around 38GBP.

And BTW, I am a householder. ukgalacticathotmaildotcom.

Jerzed, that's great and I'm going to follow this through until I crack it. Clearly you have a good grasp of technical issues and your willingness to share your expertise deserves respect. I'll report back on progress though this forum. Best regards

 

[Jerzed]

Glad to help. Personally, I think it's a good boiler because it's so easy to dismantle.
There are known problems but are very easy to fix. Let me know how you get on. I have just fixed the same problem and it's running like new. I just love (not) the "professional" prima donnas who won't help, and then charge telephone numbers. I run a handymanand decorating service as my day job. Google the part numbers, plenty of suppliers. If you were nearby, I'd do it for you.

 

[Jerzed]

Before I forget, if you are ordering parts, buy a spare diaphragm for the diverter on the right extremity. If you get hot water only if the heating is running, it's a perforated diaphragm. Common to ALL combis. If you get a lockout, especially after crappy weather it is usually a couple of drops of water in tube connecting the pressure switch inside at the top right. Disconnect the power first, exposed terminals. Only after eliminating this suspect the PCB. Refurbished PCBs are available, a place in Watford I think, although I got one on eBay for 50gbp about 4 years ago, a 15minute job to change.
Regards. Jeremy

 

[Jerzed]

Make sure of not just the model, but also the serial number as there are several type variations and layouts.

 

[numbersman1]

Make sure of not just the model, but also the serial number as there are several type variations and layouts.

Jeremy, back home and back on line after a hectic Saturday helping out my daughter. The extra information is extremely valuable and will be be acted as soon as I get a free run (work permitting) to start the repairs ( prob wed,thurs , fri next week). We're managing at the moment by letting CH warm up and run for a short while then switching off at the mains but this is only a stop gap measure.

I agree your comments on the 'telephone number' costs on invoices that signifcantly overvalue the service provided and ordinary people on average incomes struggle to meet these costs. It appears to play on the panic which is human nature when you can't run hot water nor keep warm. There are overheads (professional subsriptions/ vehicles) etc and no one is saying 'work for pennies' but 'Fair Trade' exists elsewhere.

Finally, at the risk of repeating myself, your approach to helping others should be applauded!

kind regards Phil (Derbyshire)

 

[Jerzed]

Another useful point. When you drain down the boiler, make sure there is no debris in the pressure relief valve or it will drip on refilling and you will lose pressure.

 

[westvale]

[I had a similar problem and went through all of the electronic tests on the PCB which were all OK.
The problem turned out to be the primary flow switch. This is a microswitch that is operated by a pressure valve.

There was a slight seepage from the pressure valve and the switch was getting steamed until it filled with water and shorted out. This was plain to see.

There are 2 such switches and it is worth checking both. They are removed by sliding out a thin spring clip from the stem.

Remedy was to drill a hole in the switch plasic housing to let the steam escape. You can also take the microswitch apart and dry it. It simply snaps apart and together, be careful to reassemble it correctly though as some bits can drop out.

This worked perfectly, but eventually the rubber seals on the pressure valve will need replacing.