glowworm c30 fault F75

[johnhenstock83]

evening all,

 

very quick question, if I may:

 

we have a 14 months old boiler, a glowworm c30. everything worked flawlessly until tonight when we both came back from work. when we left in the morning, heating was on (21 degrees on thermostat, always on). hot water was working. I switched the heating off (thermostat) when I left, no point heating the house for 10 hours. when I got back home, I switched the thermostat back to on, but the boiler wouldn't function. it had a cross symbol on the screen.

 

I tried resetting it, it threw a F75 error.

 

I then found this video online https://www.youtube.com/watch?v=PEibsWnVIDQ and followed the instructions. added 2-3 secponds worth of pressure, manually, currently at 2.0 bar, and low and behold, it works again.

 

I already called my plumber, he'll drop by first thing tomorrow morning. it won't explode until then, will it?

 

thanks

 

[ProDave]

If it is dropping pressure slowly, you have a leak, that might be hard to find if it is just a drip.

 

However if you get the heating up to temperature, turn the heating off and let it cool down, and then it drops pressure quickly, it is likely to be a failed expansion vessel.  Your plumber will be able to check that when he comes.

[SimonD]

F75 typically relates to the water pressure sensor but can sometimes also be caused by a faulty pump.  To get rid of the error, you usually have to re-pressurise above the normal 1-1.5bar to get it working again. It's common to see people having to re-pressurise so much it ends up out the prv when the system gets hot. It won't blow up. However, if your boiler is just 14months old, it's not your plumber you need to call but Glow-worm as they'll sort it under warranty - your plumber shouldn't really touch it.

[johnhenstock83]

Thanks both. The only issue with the warranty is that we bought the house with a brand new boiler, no paperwork is available, so difficult to prove it’s still under warranty.

[johnhenstock83]

engineer dropped by, it's the pressure sensor. no danger at all, boiler running (you can start it manually), part to be replaced today or tomorrow.

 

always the pressure senor... just can't seem to handle any pressure.

Edited March 1, 2023 by johnhenstock83