Grant Vortex 26 questions

[Nathzy01]

Hi guys, looking for some advise on my Grant Vortex 26. Had a big leak for the heat exchanger last year which ran down to the hot water pump and shorted it out. I replaced the pump with new and new olive on the offending pipe. But since then have a couple of issues.

1) The hot water tank sounds like it has air trapped in, I can hear it gargling and kettling. I have bled out the central heating system but figured this would be a separate system to the hot water. How would I go about bleeding the air out of the hot water tank, I can’t see any visible bleed points only automatic air vents?

2) The hot water pump runs constantly when the hot water is selected on the controller inside, it doesn’t just come on when a hot tap is switched on. So it’s constantly pumping, if I switch the hot water off on the controller the pump stops but as soon as I switch it on the pump runs. The only flow switch I can find is on the main cold incoming supply to the boiler, I’ve tested it and it’s working but this shouldn’t control the hot water pump?

If anyone has any experience with these boilers it would be greatly appreciated!

Thanks

 

[exedon2]

Grant now only fit one auto air vent on there combi boilers when they leak (most eventually do) we replace them with manual valves.
Depending on how old you boiler is it has either 2 small driver boards or one large one.
The hot tank thermistor lead is plugged on to board right hand side on current board .
Check its properly located ,
Until that thermister is satisfied hot pump will run.
If you have a multimeter and are competent to use it check flow switch connections you should only have live on one side of connector plug.
If you still have power to hot water pump with flow switch closed and tank up to temperature it could be thermister or more probably board..
Have seen a few go after major leaks in boiler or even customers spraying water about when trying to get air out.

 

[Nathzy01]

Grant now only fit one auto air vent on there combi boilers when they leak (most eventually do) we replace them with manual valves.
Depending on how old you boiler is it has either 2 small driver boards or one large one.
The hot tank thermistor lead is plugged on to board right hand side on current board .
Check its properly located ,
Until that thermister is satisfied hot pump will run.
If you have a multimeter and are competent to use it check flow switch connections you should only have live on one side of connector plug.
If you still have power to hot water pump with flow switch closed and tank up to temperature it could be thermister or more probably board..
Have seen a few go after major leaks in boiler or even customers spraying water about when trying to get air out.

Thanks for you’re reply and advice. It’s an older model, looks to have 1 manual and 2 auto air vents. It also has 2 control boards.

I’m going to replace all air vents, is there a procedure you would follow or just open manual bleed valve, open CH/HW pump bleed screws and then bleed CH system?

I have a multimeter, but the only flow switch I can find is on the main cold incoming, which is switching correctly. What is the best way to check the thermister?

Thanks

 

[SimonG]

Boards are delicate on the old Grants.

 

[exedon2]

As you have a multimeter I would have it to hand with everything exposed on boiler then ring Grant technical.
The will walk you through all required tests.
They really are excellent in stark contrast to most other oil boiler manufacturers who will not even speak to you if boiler out of warranty.
If you do need a new board we use heating world of spares
Next day delivery they only list one board for that boiler as they are identical just connected differently.

 

[bennettjc]

Our Grant Vortex external Combi 21e has all the lights on except the flow light was working before Christmas, lost pressure (which has been rectified) now will no longer fire up (oil is a 1200 litre full tank). any ideas?

 

[SimonG]

Full tank you say! Run out of fuel. Or not repressurised high enough.

 

[bennettjc]

Full tank you say! Run out of fuel. Or not repressurised high enough.

No it was at 500 when auto refill decided it needed another 700 litres

 

[exedon2]

Flow light will only be on when hot water demand.
When was it last serviced?
Best thing get a competent oil engineer.
On the earlier Grant combi's we get rid of pressure switch its not been on new boilers for several years.
Just link it out on board no more low pressure shut downs.

 

[bennettjc]

Flow light will only be on when hot water demand.
When was it last serviced?
Best thing get a competent oil engineer.
On the earlier Grant combi's we get rid of pressure switch its not been on new boilers for several years.
Just link it out on board no more low pressure shut downs.

Thanks, the boiler was installed new in 2019. It is hard getting a competent oil engineer around Trowbridge Wiltshire. 8f you know of any just let me know. Thanks