Boilermate overflowing - what is repplacing the water?

View previous topic View next topic Go down

Boilermate overflowing - what is repplacing the water?

Post  gwltabb on Thu Apr 25, 2013 10:41 pm

Hi

I'm trying to get to the bottom of a problem after draining down and re-filling my system (no problems with blocked cold feed as header emptied and re-filled fine). Now when the boiler runs warm water comes out of the overflow pipe. My boiler seems to be mildly kettling which is the source of the problem.

My question is, there is a reasonable amount of water being lost when the boiler runs out of the overflow, yet as the header tank is 3/4 full and well above where the ballcock would start letting water in from the cold feed, why is the cylinder not dropping water level? If there is no other source for the water to come from, would I be right in assuming it is being replaced by air due to the kettling? That would make more sense if there was air coming out of any of the radiator or pump bleed screws but there is no evidence of any.

Could you claarify this for me and any other advice?

gwltabb

Posts: 5
Join date: 2013-04-25

View user profile

Back to top Go down

Re: Boilermate overflowing - what is repplacing the water?

Post  mike on Fri Apr 26, 2013 8:12 pm

Boilermate as in?
What model?
Mike

mike

Posts: 1342
Join date: 2009-10-09
Age: 61
Location: Norwich

View user profile http://www.mgch20.co.uk

Back to top Go down

Re: Boilermate overflowing - what is repplacing the water?

Post  gwltabb on Fri Apr 26, 2013 8:17 pm

Hi Mike - Boilermate II

gwltabb

Posts: 5
Join date: 2013-04-25

View user profile

Back to top Go down

Re: Boilermate overflowing - what is repplacing the water?

Post  mike on Fri Apr 26, 2013 8:21 pm

Could be the internal DHW coil gone.
Turn off water to the unit.
Empty header tank to a level which is acceptable.
Turn water back on and see if it rises in the header tank.
If that is ok.
Check the boiler pump, try it on 2 if on 3.
If you really had a lot of sludge in the system etc, then the unit would vent / pump over.
I take it you have checked the ball valve in the F& E tank.
Mike

mike

Posts: 1342
Join date: 2009-10-09
Age: 61
Location: Norwich

View user profile http://www.mgch20.co.uk

Back to top Go down

Re: Boilermate overflowing - what is repplacing the water?

Post  gwltabb on Fri Apr 26, 2013 9:23 pm

Hi - thanks for the reply.

If it was the internal DHW coil wouldn't that overflow constantly not just when the boiler is running? Also would be a bit of a coincidence for that to occur just after a drain down (not that it couldn't happen!).

I can't set the pump any lower it is on 3, if I set it to 2 it really starts kettling and banging (that has always been the case not just now).

What is the difference between venting over and pumping over? As I said the overflow only starts to trickle when the boiler is running and the boiler definitely makes a kettling noise.

My main confussion is why the header tank level does not drop if there is no water being replaced. I will check the ball valve by letting some water out but I'm pretty sure it is not filling from there as this only occurs when boiler is running.

gwltabb

Posts: 5
Join date: 2013-04-25

View user profile

Back to top Go down

Re: Boilermate overflowing - what is repplacing the water?

Post  mike on Sat Apr 27, 2013 12:16 am

The coil if gone is NOT as easy or how you would think it would be.
In fact it can be hard to detect.
And can / be worse when the boiler is running / heating the unit up.
I know because I had one like it.
As I said take some water out of the header tank manually.
Isolate the ball valve.
Then run it.
Is the water coming up the vent on the F& E tank?
Or up the cold feed?
You have got a problem hence the kettling etc.
Remember the vent is the safety route.
And if that is the easiest place rather than the return etc then this will occur.
Now I could say a bit more.
But you tell me what you done ref the drain down.
The 1st 2nd and 3rd things etc.
Then I can say more.
Mike

mike

Posts: 1342
Join date: 2009-10-09
Age: 61
Location: Norwich

View user profile http://www.mgch20.co.uk

Back to top Go down

Re: Boilermate overflowing - what is repplacing the water?

Post  gwltabb on Sat Apr 27, 2013 3:21 pm

Hi Mike - many thanks for your reply. I have done what you suggested.

When I isolated the ball valve and emptied the F&E tank, the water was coming back into the F&E tank via the cold feed, not via the vent pipe. I then turned off the water mains to the whole house and tried again, and this still occurs. The boiler is kettling, and sending the water back up through the cold feed? Please explain! I'm assuming this isn't the internal coil as the water mains was turned off therefore the water cannot be coming from outside the coil?

When I drained down, I emptied the system completely (water coming out is clear, as I fill with inhibitor), fixed the radiator, then re-fiilled the tank from the F&E cold inlet, bleeding the radiators as I went. I then poured in inhibitor. Everything was working fine until the evening when there was a very loud noise coming from the boiler, as if something had got stuck in it, air or debris. I turned it off that night and from the next morning onwards, the boiler has a mild kettle which is causing this issue. I thought it may be the pump or heat exchanger causing it but now I need to know why the water would come back up the cold feed pipe?


gwltabb

Posts: 5
Join date: 2013-04-25

View user profile

Back to top Go down

Re: Boilermate overflowing - what is repplacing the water?

Post  mike on Sat Apr 27, 2013 3:26 pm

Well if it not the coil.
Then the unit / boiler pump is pumping up the cold feed.
Why.
Because you have;
An air lock.
A blockage as in sludge etc.
A lazy pump?
What if you run the heating pump?
Is it better? As in noise?
You could try boiler silencer etc, to clear the noise in the boiler.
Try turning the boiler down and running on low to see what happens.
You cold have a blocked return pipe on the unit or pump valve.
Mike

mike

Posts: 1342
Join date: 2009-10-09
Age: 61
Location: Norwich

View user profile http://www.mgch20.co.uk

Back to top Go down

Re: Boilermate overflowing - what is repplacing the water?

Post  gwltabb on Sat Apr 27, 2013 3:58 pm

If I run the heating it is definitely better. It gets worse as the cylinder gets up to temperature. Would it be worth another complete drain down and flush water through to try and fee the blockage or air? Is it unusual for the water to come back up the cold feed?

gwltabb

Posts: 5
Join date: 2013-04-25

View user profile

Back to top Go down

Re: Boilermate overflowing - what is repplacing the water?

Post  mike on Sat Apr 27, 2013 4:10 pm

Be better to drain down.
And the boiler too.
Put in sludge remover and fill.
Run the unit and boiler pump first then later the rads.
You will have to drain / flush out later inc all rads more so each rad drop / down stairs.
But run sludge remover for at least a week poss 1 month.
Mike

mike

Posts: 1342
Join date: 2009-10-09
Age: 61
Location: Norwich

View user profile http://www.mgch20.co.uk

Back to top Go down

View previous topic View next topic Back to top

- Similar topics

Permissions in this forum:
You cannot reply to topics in this forum