Hot water but no heating - Vaillant boiler

[luke_s]

Hi All,

Hope someone out there can help!

We have a Vaillant ecotec plus 832 and nest thermostat. Tried putting the heating on this afternoon and isn't working at all, but have still got hot water.

There is no fault code showing, and pressure is fine, 1.6.

I put it into service mode and selected live monitor after turning heating on with thermostat. It goes through a few different codes from s.01 to s.04 then to:

S.07 Heating Mode: Pump Overrun.

And it just stays on that or sometimes S.00 Heating: no heat demand. If I turn off request at thermostat it does respond to that, so don't think that's an issue. I've also reset thermostat.

Towards end of August the boiler was losing pressure and leaking from somewhere. British gas engineer replaced a sensor and diverter valve I think. They can get an engineer out again but not until Tuesday earliest and they usually postpone in my experience, so wanted to see if I can do anything before then myself?

Cheers,
Luke

 

[ianmcd]

post pics of your controls and boiler panel when it wont fire

 

[CBW]

Do you have an onboard timeswitch too? Check the flow and return valves under the boiler too.

 

[luke_s]

post pics of your controls and boiler panel when it wont fire

So initially I get the display with the bar on the left with flame at the top on left side of the display. Nearly full, then it shows nearly empty. Simultaneously the radiator symbol will flash. The bar on the left disappears. A flashing egg timer symbol then appears and when that goes off, there is just a static radiator symbol left. At that point it will show the s.07 code when I go into that menu.

Bit tricky to take photos as boiler is in the loft and no lights up there!

 

[luke_s]

Do you have an onboard timeswitch too? Check the flow and return valves under the boiler too.

No timeswitch. Display looks more or less like attached photo.

 

[oldbutnotdead]

Is this your first run of the heating this year? Pump may be stuck...or motorised valve gummed up (if you have any fitted)

 

[luke_s]

Yeah it's the first time we've attempted to put it on. Aside from end of August when British Gas replaced some parts, they tested the heating then.

No idea if there's a motorised valve sorry.

 

[CBW]

Did you check the flow and return valve under the boiler like I suggested?

 

[luke_s]

What should I be looking out for/how would I know if there's a problem there?

 

[polesapart]

Look for one of these on each of the two 22mm copper pipes at the far left and right sides, under the boiler.

Picture shows valve in closed position. If they look like this they need to opened with a hex (allen) (?4mm) key or gurt screwdriver, turned 90 degrees so that the large slot is in line with the valve.

 

[CBW]

Look for one of these on each of the two 22mm copper pipes at the far left and right sides, under the boiler.

Picture shows valve in closed position. If they look like this they need to opened with a hex (allen) (?4mm) key or gurt screwdriver, turned 90 degrees so that the large slot is in line with the valve.

Yes 4mm or even 4.5mm

 

[luke_s]

Look for one of these on each of the two 22mm copper pipes at the far left and right sides, under the boiler.

Picture shows valve in closed position. If they look like this they need to opened with a hex (allen) (?4mm) key or gurt screwdriver, turned 90 degrees so that the large slot is in line with the valve.





View attachment 284777

Thanks for clarifying. It looks like both are already in line, have attached photos.

Anything else I could check before British Gas (hopefully) turn up tomorrow? Thanks

 

[CBW]

I’d say no and it’s likely the diverter valve.