Grant Vortex Combi 21e no central heating

[Christopher52]

Hi,

I've recently put some heating/hot water pipes into the floor as there were exposed previously. On refit of the pipes i've gone to test the boiler functionality however, the central heating won't fire.

The hot water works perfectly.

There is no CH light on the boiler and the return pipe warms up slightly however, there is no hot water on the supply side and the pump doesn't run. If i've accidentally switched the pipes over would this cause this issue?

Thanks for any help,

Chris

 

[Deleted member 120897]

Could be an airlock, but if there’s no light, could it be whatever controls the heating, eg the room thermostat not high enough?

 

[Christopher52]

Could be an airlock, but if there’s no light, could it be whatever controls the heating, eg the room thermostat not high enough?

Hi, how would i go about clearing an airlock please? The burner isn't it lock out mode either.

I've set the thermostat at 30c and put the timer on constant to rule that out.

Thanks,
Chris

 

[SimonG]

If theres no central heating demand light then it's not getting a signal to run central heating.

 

[exedon2]

Try pushing in manual overheat reset.

 

[Christopher52]

If theres no central heating demand light then it's not getting a signal to run central heating.

If theres no central heating demand light then it's not getting a signal to run central heating.

Hi Simon,

I've just wired in a brand new thermostat and four new wires directly into the boiler to test if there's a fault with the thermostat/wiring. The fault still remains.

Is there another way of testing whether the boiler is getting a signal to run the central heating?

Thanks

 

[Christopher52]

Try pushing in manual overheat reset.

Hi,

I've given that a go. The boiler resets but the CH still won't fire. Hot water still running ok.

Thanks

 

[Deleted member 120897]

Is there another way of testing whether the boiler is getting a signal to run the central heating?

Yes, testing for return voltage, and in some cases a supply voltage, another way might be to link out at the boiler, but that still doesn’t confirm much.

 

[exedon2]

If you have a multimeter and are competent to use it check if you have a live feed on 6 (heating pump )
If your boiler is feed by a 5 pin plug check you actually have a live feed on heating feed.
It is known for circuit board to fail on heating side particularly if water has somehow got in (not enough care when venting heating pump usually)

 

[macrut125]

Hi.....I experienced same issue.........I called out the Grant engineer who explained to me,.......
The Grant Combi oil boiler is hot water priority......when the boiler starts, it will run with hot water only, until the hot water supply is up to temperature. Then the heating kicks in.
So wait and iot will work, after 5 minutes or so.