Halstaed finest Gold lockout

[scotty99]

Can anyone help I have had 2 engineers to look at my boiler but it's still not right, it has an intermittent fault that keeps locking out only when using DHW it’s fine if running the heating but when I turn on the hot water after about 1 minute it lockout, I reset boiler heating work ok again but I get the same result if I run the water again, so far I the engineers have had put a new PCB board in have cleaned the venturi, and flow sensor valve

 

[scatmanjohn]

Does it lock out as soon as you turn the tap on or does it run for a bit first ?

 

[ChrisR]

ANyone checked gas rate, thermistors, temperatures - in other words overheating , or symptoms of it?

 

[scotty99]

System run ok for about 1-2 minutes you now just enough time to get into the shower and get your hair wet before it goes cold, the last engineer said it was not overheating and the first engineer tested the thermistors and did change DHW for the CH worked ok for 2 days before it started doing it again

 

[Rob]

how did they clean the venturi?

 

[scotty99]

don't know how they cleaned the venturi, but if it was that it would lockout on heating that still work ok if i reset the boiler after it locked out on DHW

 

[scatmanjohn]

don't know how they cleaned the venturi, but if it was that it would lockout on heating that still work ok if i reset the boiler after it locked out on DHW

Not necessarily.

 

[Rob]

if all they did was give it a good blow through then theres a good chance its this.

it needs removing and cleaning out with boiling water.

 

[scotty99]

I have just check the voltage at modureg valve, pins 30 and 31, when the heating is running the voltage is steady at about 14 to 15 volts but when I turn on the hot tap to call for DHW the voltage varies from 4volts to 19volts in large jumps is this normal, the manual say it should be between 2.5 to 20Volts

 

[Agile]

Thats fine!

In any case the boiler is going off completely according to your info.

It sounds to me like a pretty simple fault to identify when in front of the boiler. I like boilers which reliably exhibit the fault to give me the opportunity to work on it.

Tony