Glowworm Ultimate 50FF tripping (Overheating)

[LittleEagle]

Hello,
I have got an open vented heating system with Glowworm Ultimate 50FF boiler. The system keeps tripping off now and then. The company which covers the boiler said its a stat problem and replaced it. This didn't fix the problem so later they said its a sludge problem and asked me to get it power flushed. Since, I had drained the system last year and was using an inhibitor hence I cleaned the system with the Fernox cleaner and with DS-40 but the problem isn't resolved. I called a independent Corgi registered engineer who serviced the boiler and said that the fan was not moving smoothly and he aligned the blades properly. He also decreased the thermostat temp to 60 degrees. The boiler worked fine but water was not hot enough so I increased it to 65 degrees. But, the boiler was still tripping. Now, I have lost trust on the engineers coming from the company. I have emptied the system a number of times and bled the radiators as well but still no luck. Can anybody point me in the right direction?

 

[gas4you]

Do we assume it was the main boiler stat that was replaced or the overheat stat?

 

[bengasman]

When does it trip, during operation or within 2 minutes after it stops. Open vent systems are prone to sludge so their powerflush advise could well be correct

 

[LittleEagle]

I am not sure what you mean by the main boiler stat but the part that was replaced is located on the boiler and it has the Min and Max Knob.

The boiler sometimes works for a couple of hours fine then it trip. Somedays it trips a couple of times and somedays it trip once or it doesn't trip at all.

 

[tryitandsee]

Intermittent low flow rate through the boiler, maybe the pump playing up. Can you increase the pump speed on your system? if so, try doing so.

 

[LittleEagle]

The pump is running at max level speed

 

[kevsterdiy]

The pump is running at max level speed

As per my other post you found, I'd put my money on pump over run not being wired up correctly. Of course depending on how long it's been doing it/how long you've lived in your house.

All my previous owner said was 'oh when it trips out just press this button'

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