Grant Vortex HW fault

[SteveMagee]

Have an external grant vortex.
Only using it for the hot water at the mo as house is under renovation.
When I turn the water on the burner fires up as normal, then stops after about 30-45 secs, HW pump , power and demand lights still on no other faults showing.

Can someone possibly point me in the right direction, thanks

Steve

 

[Norcon]

Any oil in the tank?

 

[SteveMagee]

Yes the tank is half full, It will run each time for about 45 seconds, it probably misbehaved after a power cut last week in the high winds here, might be worth looking at the oil bleed screw but if there was air in the system would it not fire up at all ?

As stated i'm only using the hot waterat the moment, it it possible there is an airlock on the HW side of things ( not CH) ?

cheers

Steve

 

[diverdee]

does the heating work first thing to check.is the hot water thermostat turned up on boiler

 

[oilhead]

There are three autoair vents on the DHW pipework and heatstore. Make sure they are all bled. Also, is the dhw pump running?
Other possibility is the sensor or the pcb. Take the sensor out of the pocket and see if the fault is still there.

 

[SteveMagee]

Thanks for the info, both the CH and HW use the same pump, I swapped the pumps over, what's interesting is when the burner stops the HW pump light is still lit but the pump stops working, I'm hoping its not a PCB fault but possibly looks that way. Were is the sensor located.
cheers

Steve

 

[oilhead]

There is a lead from the pcb that goes into a pocket on the front of the heatstore.
Ifthe pump stops running, but the light is still on, is there still voltage to the pump or is it dead?

 

[SteveMagee]

Sorry i posted the below as a new post

Hi, thanks again for all the info,

Turned it on today from cold the burner came on for about 10 mins then cut out, the demand light and the HW lights stay on. I had a quick look at the control panel, 240 volt to the motor when the burner stops. ( already swapped the motors around ). Does it sound like its a burner problem now to you ?

on a normal cycle when the burner switches off should the demand light go off and the pump stop. ?

The sensor in the heat store is that the one at the front to right of the expansion tank looks like its behind a heat exchanger or something ? if so that is well secured in with a hex nut.

Read more: //www.diynot.com/forums/plumbing/grant-vortex-hw-fault.394873/#ixzz2uWJpjAy2

 

[SteveMagee]

Also seems that just before the burner cuts off there's a knocking sound ?

 

[oilhead]

If you are not having to reset the burner, then there is no burner fault. If it runs and gets the heatstore up to temperature, then your problem is with the temperature controls or the flow switch. Follow the flow chart in the manual and you should identify the fault. This is what professionals do and it works. Jumping from one part of the process to another with no logical sequence will need you to be very lucky.