grant vortexblue external combi no hot water

[fozzie52]

Today I had to isolate a radiator from the central heating circuit. It's just a small towel rail thing and I just joined the plastic pipes together where it was for the time being.

The central heating pressure had dropped to 0 by the time I had it sorted. I added water and bled some radiators and it seemed fine.

Later when I went for a shower there was no hot water - this boiler has had issues if the pressure gets to low and you have to top it up periodically but it should be high enough now.

I took the front off the boiler and the lid and found 3 bleed points which I bled well, and have run the hot taps for a long while.

Still don't have any hot water, any ideas?

 

[fozzie52]

I can hear it exhausting occasionally but still not hot water. pump light is on but I couldn't feel it turning at all - is it noticeable?

 

[Johntheo5]

Does the boiler/burner fire up on CH?, if so, assuming the HW circ pump is running OK then you may have a problem with air in (DHW) primary water side circulating through the plate heat exchanger.
The flow light isn't illuminated on the panel with a DHW demand, not sure what drives this but would have thought it would/should be a flow switch on the DHW side but you say this is flowing with a good flowrate?.
Will have a look at the boiler MIs later, if you have a link to them, you might post them on.

 

[fozzie52]

Central heating also appears to be not working - but I had put it on earlier and seemed fine. The flow light appears to be working I think I just had turned it off for the photo.

The hot water pump has 240v to it, the CH pump doesn't (with the CH on). Should you be able to feel it running?

 

[fozzie52]

Well I'm moderately embarrassed...

I just turned the burner off and on again... and it burst into life and I now have hot water. I DEFINITELY did that yesterday to no avail but maybe I hadn't bled stuff properly at that point?

I still have no central heating, but at least I can have a shower while I try and work out why. The CH pump appears to not be getting a feed still.

 

[fozzie52]

Central heating kicked on too.

 

[Exedon]

The Grant combi's can be 'difficult ' to clear of air the air valve on the return will probably need opening a number of times.
Never ever use the on/off switch on the boiler when it much more than a year old they break for fun!
If you need power off just pull plug out .
Assuming you have the ch light on when heating selected it probably just air in pump.