Problem with Potterton boiler system

[Blueboy0333]

undo the black nut on the pump and check the pump is spinning.

Perhaps a stupid question but can I do this while the system is running or do you mean to power it down and manually check that the pump isn't seized

 

[baxpoti]

Either blocked cold feed or duff pump. The cold feed is the pipe that fills the system from the small header tank in the loft.

Water is heating without a problem

 

[Blueboy0333]

Either blocked cold feed or duff pump. The cold feed is the pipe that fills the system from the small header tank in the loft.

Thanks for this...

What's the best way to check the cold feed and unblock it (assuming it's blocked)

 

[picasso]

open a drain off on one of the ground floor rads, as the water drains listen for the header tank filling.

 

[baxpoti]

Thanks for the quick reply

yep...I've got no problems in terms of hot water so I'm assuming the boiler is heating that ok..

 

[picasso]

just had another read through this thread, what kind of valve have you got and when it was replaced did you try the heating ,

 

[Blueboy0333]

just had another read through this thread, what kind of valve have you got and when it was replaced did you try the heating ,

The motorised valve is a MPE332 (Myson Power Extra)...

Just checking it out now for the code as I saw that
1) The CH light is on (Water is off) which should be correct as the water is hot whereas the heating is "required"
2) The lever for switching from auto etc is "flapping" about. Shouldn't this be on a spring and is this a problem ? It's currently in the AUTO position but could easily slide about

The heating has worked since the valve was replaced. Should probably add that it was only the motorised element that was replaced rather than the valve itself

 

[numpty1]

numpty1 wrote:
undo the black nut on the pump and check the pump is spinning.


Perhaps a stupid question but can I do this while the system is running or do you mean to power it down and manually check that the pump isn't seized

turn power off slacken nut give it a slight tug untill you feel resistance,turn power on to pump and the nut should spin,if you pull too hard the plastic nut comes off and reveals a brass/steel nut head this should spin freely.have a towel under the pump to collect the water.

 

[picasso]

is the pipe connected to port a getting hot? as already said it could be the pump or the motorised part of the valve is moving but not the ball inside

 

[Blueboy0333]

is the pipe connected to port a getting hot? as already said it could be the pump or the motorised part of the valve is moving but not the ball inside

Yep...All pipes to and from the motorised valve are red hot

 

[Blueboy0333]

Ok...

Tested the pump this morning and it seems to be spinning fine so I'm assuming the pump is ok

 

[kevindgas]

easy to find out if cold feed is blocked. if rads are not heating properly they are possibly full of air.

turn the water supply off, then bleed a few rads does the water in the header go down? if it does then the feed is not blocked. turn the water back on!

air in the rads may also stall the system.

 

[picasso]

if the boiler is running and the valve is opening to the rads it can only be one of 3 things.. lack of water , faulty pump or system blocked, I would go with faulty pump

 

[gassafeman]

With Central Heating Systems dont ever 'assume' as it make an 'ass' of 'u&me'.

Your circulation seems poor so test it. Your pump would be the first component to test. A spinning pump does NOT mean its working. The shaft often breaks from the impellor, which leaves a laymen thinking it is working. The Motorised valve... another assumption.

Tie the header tank ball valve up and drain a gallon out of the system. If header is empty then your cold feed is fine.

Paul

 

[Blueboy0333]

With Central Heating Systems dont ever 'assume' as it make an 'ass' of 'u&me'.

Your circulation seems poor so test it. Your pump would be the first component to test. A spinning pump does NOT mean its working. The shaft often breaks from the impellor, which leaves a laymen thinking it is working. The Motorised valve... another assumption.

Tie the header tank ball valve up and drain a gallon out of the system. If header is empty then your cold feed is fine.

Paul

Fair enough !!!

I'll try all the advice given over the last few posts (and thanks to all the posters)..

In terms of the pump how can I test it (assuming the "spinning test" isn't giving me a definitive answer) ?