Halstead Finest Gold Safety Lock Out

[spbctjr]

Dear All,

Having read a few posts on here regarding this combi boiler, I've been through a few trouble shooting steps already.

From electrical power off and central heating off, switching on the power we have the green light on, the fan spins, then after about 5 seconds the red safety lock out comes on constantly. The boiler doesn't get as far as attempting to ignite.

The override switch has not been triggered. Pressure is 1bar+.

If I turn off the power and turn back on, then run a HW tap for a couple of seconds to trigger the HW flow switch during the start up sequence, the red lock out light doesn't appear, but the fan stays on.

If I then switch the central heating or a HW tap on the lock out will come on after a few seconds.

So far I have checked the fan pressure switch (by shorting the wires). Have also visually checked the the fan and assembly and it all seems clear. So I doubt the vent is blocked.

I have read you can bypass the main flow switch by simply removing the wires from the microswitch. However, this did nothing different. I also noticed that the small pin that is pushed out by the main flow switch diaphragm when the water is flowing was pushed out, even with the system off. I pushed it back in manually and it remained in place even when the system was restarted. i.e. not pushing the microswitch.

Does this mean either there is no flow (i.e. pump fault or PCB fault stopping pump from running) or the diaphragm has failed.

If the diaphragm has failed then why doesn't bypassing the flow switch allow the system to get to ignition (or is this check incorrect - I suspect and hope it is). Is there any easy way to tell if the pump has failed. Feeling the pump there is little if any vibration at any point. But presumably the pump won't start unless the flow switch works.

I tried to check the diaphragm but wasn't able to isolate the flow, so water was still under pressure and as some idiot installed it directly over the mains fuse box I stopped !

Just to confirm to isolate and drain the boiler for changing the diaphragm on the main flow switch. I need to close the inlet and outlet for CH, I assume the cold water in doesn't need to be shut off, but I shut it off anyway. I then opended the drain valve on the central heating flow on the boiler. The pressure dropped to about 1/2 bar and then was reduced to a drip. To me it looks like the CH flow or return valves aren't shutting properly? Which means I need to drain the entire system? Whn I reopened the valve the pressure remained at 1/2 bar which again indicates to me the valves aren't closing fully. Any pointers on this most welcome. Both flow and return did seem to be very stiff, but were turned fully 90 degrees as indicated in the manual.

Many thanks for any help or advice.

Also, for anyone interested the service and installation manual can be found here for free http://manuals.aonly.com/index.php?d=Boilers/Halstead&f=HALSTEAD FINEST GCNo.47-333-06.pdf
Thanks,

Toby

 

[ChrisR]

Sounds like you've got to the point where you need someone with experience of this boiler and a bit deeper knowledge of how the bits work. I think you have some misunderstandings... Full answers could take a few pages. Obviously the water flow proving parts sound faulty so you could start there.

 

[spbctjr]

Hi Chris, thanks for the quick reply.

Yes, the flow proving seems to be at fault. But as the push pin doesn't come out then the buggered diaphragm is a reasonable guess? If it is simply the diaphragm I really don't want to get a plumber out to swap that.

I assume the recommendation for a professional is that you suspect it isn't a simple job or that I don't understand what I am doing (hence the forum post) or it is gas/corgi related and I appreciate you don't give advice on any gas related work.

So in you're opinion, if it is a major fail ( £200+) is it worth calling it quits, saving the expense and getting a new boiler fitted, as the boiler is ten years old, it is a Halstead (which get quite a lot of stick) and I'd rather spend a couple of thousand now and save £200, than spend £200 now and need to spend £2000 in 12 months anyway.

Cheers,

Toby

 

[commercialman]

Depending on the model # some of these early Halsteads had issues with the fan venturi which when restricted would cause boiler lockout , you need a registered gas engineer as the fan assbly will need to be removed , failing that it could become expensive if PCB has taken a hit (relay issues).

 

[spbctjr]

Having just had time to do a final check. I manually activated the pump flow switch and the boiler did not lock out. It also attempted to ignite when the flow switch was manually activated and CH was turned on.

So, switch is working. But flow isn't. So again wondering if this is likely a faulty pump (as I can't feel any vibration from the pump when the system starts up and I'm assuming the pump should activate for the test procedure on start up) or is it a PCB issue? Either way I'm assuming these are going to be relatively expensive to replace.

So recommendations for a new boiler?

Cheers,

Toby

 

[Gasguru]

If you turn the boiler on regardless of any demand it will carry out a power on self test. Part of the test is to run the pump and check the flow switch operates.

Remove the screw in the centre of the pump..a small amount of water will dribble out. Check the spindle inside is free to turn and whilst the screwdriver is located in the spindle slot create a demand. Check the pump runs and has sufficient torque. New pumps are around £60...it's standard 6m Grundfoss head.

If the pump appears to be ok there may be a partial blockage. That's going to be a lot more tricky to find..

These boilers often get unfairly slated...apart from the carp front panels thay are well built. Providing there are no major faults they are well worth repairing.