Vaillant Ecotec - Radiators too hot to touch

espresso

pimento wrote: »

Thanks Espresso. The user manual doesn't tell me very much.

If turning the knob down to turn the rads temp down still leaves the pressure touching the red, will this be OK to live with until January 3rd?
Our heating only goes on twice a day, 45 mins in the morning and 90 mins in the afternoon.

The pressure will still rise and if it does get too high - above 3 Bar then the boiler will automatically lose system pressure via the pressure release valve and vent to outside.

If this does happen then you will need to re-pressurise the system back to it's normal cold pressure of 1 Bar on the gauge.

pimento

Great, thanks. I've turned the radiator temp knob on the boiler control panel down a bit and turned the heating on. It seems to be running OK, the rads are not quite as hot and the pressure is high but not as close to the red as it was before.

I do know how to increase the pressure if required.

I love this forum. Thank you all and Merry Christmas!

ormus

turn the hot water switch to full, and the ch switch to approx halfway.
you only need to turn the ch switch to full when its freezing like last year.

pimento

Ormus, it may (or may not) be pertinent that my boiler is not set to operate as a combi boiler. I have a hot water tank in the airing cupboard.

Does this matter (with regards to your instructions)?

KateLiana27

pimento wrote: »

Great, thanks. I've turned the radiator temp knob on the boiler control panel down a bit and turned the heating on. It seems to be running OK, the rads are not quite as hot and the pressure is high but not as close to the red as it was before.

I do know how to increase the pressure if required.

I love this forum. Thank you all and Merry Christmas!

We have exactly the same boiler, and yes, your central heating flow temperature on the boiler itself (top picture, bottom of the two knobs, with the picture of the radiator) was set far too high. Ours points to the 12 o'clock position during the winter, and we only had to increase it when it was snowing.

gas4you

The hot water control will have absolutely no effect unless you have a VAILLANT Unistor cylinder and a VR65 wiring unit fitted. Leave it completely turned down to off.


Set the radiator stat on the boiler to a maximum of 70.

It sounds like the expansion vessel has gone flat, extremely common on these. Usually need re-charging at least every couple of years.

Nothing to worry about for a Christmas day call out

pimento

Thanks gas4you. I'll let British Gas come as planned on January 3rd.

Many thanks to everyone who helped.

pimento

Just a quick update.

British Gas came today and it was indeed the expansion vessel at fault. Easily fixed.

Thank you for all your help.

Ruski

Glad it's sorted - Gas4you spot on!

So - out of curiosity, why does a 'flat' vessel cause overheating of the CH circuit??

Russ

pimento

Hope you're not asking me! LOL

I just left the British Gas engineer a note when I went to work and left my husband to it.