Grant Vortex combi external oil boiler overheat

[skelo]

Hi my oil boiler is not working, its about 4 years old and just been serviced about a month ago but yesterday the overheat warning light keeps coming on and the boiler shuts off. we have no hot water or hot radiators. Can this be fixed easily I have some mechanical knowledge.
thanks

steve

 

[Boilerman2]

Is this a Combi Boiler or just a regular type is it a Sealed or open vented system??

If a Combi or Sealed system the most likely cause will be a lack of water pressure in the primary system as indicated by the system pressure gauge, if this is the case you will need to top up using the filling loop refill to around 1.2 bar

 

[skelo]

Is this a Combi Boiler or just a regular type is it a Sealed or open vented system??

If a Combi or Sealed system the most likely cause will be a lack of water pressure in the primary system as indicated by the system pressure gauge, if this is the case you will need to top up using the filling loop refill to around 1.2 bar

Hi thanks for reply

it is a combi boiler and the system pressure was low so I have refilled / top up to correct 1.2 bar pressure on gauge but still shuts off and no hot water. It seems that the boiler is overheating and the heat exchanger is stone cold.
steve

 

[Gasop]

[quote It seems that the boiler is overheating and the heat exchanger is stone cold.
steve[/quote]

Is the 'warning light' at the top right of the boiler or on the front of the
burner.

 

[leakydave]

It could be that one or both of your auto air vents are blocked or closed and the boiler is not able to pump heat away quickly enough...

... or the central heating pump (Grant combis have two pumps) is not working or has an air lock as your water pressure was so low...

... or one of the heat sensors has come away from its pocket and it is not sensing the temperature correctly of the water jacket

 

[dcawkwell]

switch the hot water off. does it work ok for central heating?

 

[skelo]

It could be that one or both of your auto air vents are blocked or closed and the boiler is not able to pump heat away quickly enough...

... or the central heating pump (Grant combis have two pumps) is not working or has an air lock as your water pressure was so low...

... or one of the heat sensors has come away from its pocket and it is not sensing the temperature correctly of the water jacket

hi how can i check auto air vents are ok and how to remove air locks
thanks

 

[skelo]

switch the hot water off. does it work ok for central heating?

will try this one

merry xmas to all

 

[skelo]

It could be that one or both of your auto air vents are blocked or closed and the boiler is not able to pump heat away quickly enough...

... or the central heating pump (Grant combis have two pumps) is not working or has an air lock as your water pressure was so low...

... or one of the heat sensors has come away from its pocket and it is not sensing the temperature correctly of the water jacket

have checked air vents all ok and opened both pumps to let any air out. The problem seems to be the pump near the burner , I have checked the supply all ok 240 v but it wont turn and if put a small screwdriver in the end its quite hard to turn. Should i replace this with a new one. thanks

 

[dcawkwell]

It could be that one or both of your auto air vents are blocked or closed and the boiler is not able to pump heat away quickly enough...

... or the central heating pump (Grant combis have two pumps) is not working or has an air lock as your water pressure was so low...

... or one of the heat sensors has come away from its pocket and it is not sensing the temperature correctly of the water jacket

have checked air vents all ok and opened both pumps to let any air out. The problem seems to be the pump near the burner , I have checked the supply all ok 240 v but it wont turn and if put a small screwdriver in the end its quite hard to turn. Should i replace this with a new one. thanks

Pump has gone.

 

[oilhead]

Have you reset the high limit thermostat after re-pressuring the system?
Sre you saying you have but the light keeps coming back on? If the boiler is stone cold, it would suggest that the limit has not been reset.
Unscrew the black cap on the right hand side of the control panel and pres the white button.
Have just read that the lower pump is seized. If you de select hot water, you will still get heating.

 

[skelo]

Have you reset the high limit thermostat after re-pressuring the system?
Sre you saying you have but the light keeps coming back on? If the boiler is stone cold, it would suggest that the limit has not been reset.
Unscrew the black cap on the right hand side of the control panel and pres the white button.
Have just read that the lower pump is seized. If you de select hot water, you will still get heating.

thanks have replaced lower pump with new item and works great now phew !!

steve