Expansion Tank Overflow Issue Questions

[djedga]

Hi all,

I have an issue with my expansion tank overfilling which I have spent the last couple of evenings fault finding. I have struggled to find definitive answers to my questions.

Issue
- Boiler stopped firing on Tuesday (click, click, click)
- Overflow from expansion tank has been dripping for a few months
so I wondered if it was related
- Decided as it is affecting the boiler I'd better take a look (yes I probably should have done as soon as the drip began)...

Fault Finding So Far
Tuesday
- Turned off boiler
- Drained tank
- tank refilled back up to the overfilled level
- Bent ballcock arm down
- Boiler fired up fine

Wednesday
- Came home to overflow dripping again (a bit worse than previously)
- Ate my dinner
- Legged it to the local DIY shop to buy a new ballcock and float
- Back into the loft Tied up the ballcock via an elaborate pulley system of string over the roof beams!
- Drained the water to an acceptable level
- Turned on boiler and left
- Tank not refilling

I have left it like this today because I have a few issues:

1) The stop cock to the expansion tank and the cold water storage tank are both locked solid through lack of use (at least 7-8 years of not being moved)
2) I started to drain down the cold tank (turned off main stopcock in the house and ran taps in the bathroom) but it seemed to be taking forever so I gave up

Questions!

1) Am I safe to leave the ballcock tied up and the lid off the expansion tank for now or am I better to leave the overflow dripping?
2) Should I replace the stopcocks that have locked?
3) Am I safe to assume that as the tank is not refilling there is not a leak in my hot water cylinder, but the ballcock is the issue?
4) The expansion tank water is quite murky and sludgy, how am I best to clean it out or do I even need to bother? I'm assuming this would help the boiler and hot water cylinder to be more efficient if I did?

Thanks!

Ian

 

[PrenticeBoyofDerry]

Questions!

1) Am I safe to leave the ballcock tied up and the lid off the expansion tank for now or am I better to leave the overflow dripping?

Leaving the valve closed temporarily should be fine, whilst moving onto question two.

2) Should I replace the stopcocks that have locked?

Yes

3) Am I safe to assume that as the tank is not refilling there is not a leak in my hot water cylinder, but the ballcock is the issue?

They issue seems to be either the valve or the setting of the float in relationship to the overflow pipe. I assume you have no water entering via the vent pipe?

4) The expansion tank water is quite murky and sludgy, how am I best to clean it out or do I even need to bother?

Flushing the whole system down, then running a sludge remover/chemical cleaner through the central heating system for a few days, then draining down and introducing an inhibitor would be wise.

I'm assuming this would help the boiler and hot water cylinder to be more efficient if I did?

It would and also prevent corrosion.
Ideally inhibitors should be introduced every three years or of course whenever the system has been drained.

 

[djedga]

Thank you for the reply - has set my mind straight

There is no water coming in through the vent pipe so will get the ballcock replaced and take it from there.

By flushing the whole system down, do you just mean turn off the mains and drain the cold water tank down?

Thanks again!

Ian

 

[djedga]

So yesterday I:

drained down the cold water tank
Replaced the stop cocks
Replaced the ball cock in the f&e tank
Refilled the cold tank
Drained the rads
Refilled the rads and put some cleaner in the system

New ballcock has solved the F&E overflow issue but this morning the boiler won't start.

Have tried to bleed the rads but a couple of the bleed valves are stuck / rounded and the key won't turn them, the pump runs and is a little noisy...

Any ideas what to try next, I need to have a shower and get to work! :0(

Ian

 

[PrenticeBoyofDerry]

If you cannot open the bleed nipples, then you may have to open the nut to remove any air, depending on type of bleed nipple it would be worth changing them, pump may also need bleeding, isolate from electric before bleeding pump.

 

[djedga]

Managed to bleed 3 out of the 5 rads in the house and the pump but no joy on getting the boiler to refire..

Got it working briefly after pressing the overheat reset button but then it shut off again.

I had to get to work in the end but the Mrs can work from home so have called out British Gas to take a look (we have a homecare contract thingy with them).

I think the thermostat may have gone as to get it to even attempt to refire the thermostat on the boiler has to be set to about 5 as opposed to the setting it was on before (a little over 1).

It's got me a bit stumped so hopefully British gas won't just try to flog us a new boiler.

 

[djedga]

So the British gas guy bled all the radiators diagnosed a faulty pump, fitted a new one and left. It was running fine on full whack wither the dial on the boiler turned onto 5 and the thermostat on full.

The new pump is a grundfos alpha 2. He suggested we re-bleed the rads occasionally to rid the system of any last remaining air.

Previously the boiler was set at 1-2 and would work fine. It seemed to only now come on at 4-5.

After a couple of hours we turned the thermostat down to 21 as it seemed like a bad idea to run it constantly at full temp. The boiler cut out which you'd expect as there was no demand for ch. the pump stopped too and no lights on the front.

Now the boiler won't refire again even when the thermostat is turned back up to 30 and the boiler dial back at 5. It seems like the lack of lights on the pump means no power, a blown fuse or a faulty pump.

Have tried tripping the ch fuse and turning it back on which results in a brief period of the boiler and pump both functioning again and then it turns off and the pump lights go out again.

This is getting infuriating now.

As a side note I can't bleed the radiators they are so tight (even the ones I could do earlier)!

 

[djedga]

Turned out to be lots of air still left in the system, all running ok now!

 

[longdogs]

Turned out to be lots of air still left in the system, all running ok now!

That's British Gas for you

 

[ianmcd]

If you have BG Homecare why didnt you just call them out at the beginning ?

 

[djedga]

If you have BG Homecare why didnt you just call them out at the beginning ?

£50 excess vs cheap ballcock replacement... Plus I thought it should be "easy" should have known better!