Glow Worm Ultimate 40 FF Problem

[gbo]

Hi I am hoping someone can help me with a central heating problem....

Glow Worm Ultimate 40 FF Open vented fully pumped system

A radiator has been removed and another changed to a towel warmer.
The Programmer has been removed and refitted.

New pump fitted Grundfos 15/60 Super Selectric
New room stat fitted Drayton

After the radiator removal The first problem was that only the upstairs radiators and hot water were working. So i fitted a link pipe between the removed rad flow and return pipes. All rads were bled but still nothing downstairs. Soon after the boiler would not ignite. The fan would run only and it sounded like the pump was trying to pump water through the system with lots of gargling type noises from the pump pipework area. The boiler would fire very occasionally i think twice in total over a few days for 5 mins then cut out and back to fan running only.

The pump was changed and the boiler fired and heated up the only upstairs rads and hot water. So The system was bled using the drain cock and the downstairs rads began to heat. After about 20 mins the overheat cut out tripped and now the boiler has reverted to fan running and pump running with water swishing type noises from pump area. All rads have been bled.

A towel warmer has been fitted in place of rad and a new room stat was fitted. But still same problem.

I hope this makes sense !

Some advice would be much appreciated.

Thanks

 

[twgas]

sounds like cold feed block or at least very restricted, probably where c/f joins system.

 

[superdupergasman]

Maybe just an airlock.

The pump has been put back in the correct way??

Switch off the boiler and let the pump run for a while on its own to move water around. Switch off HW to force the air round the rads too.

 

[gbo]

Thanks for the reply.

Yes the pump is going the correct way.

The C/F seems to be ok what is the best way to check?

I left the pump to run and there was some loud water gurgling noises from it. I will leave it to run with boiler HW off see how it goes.

Thanks

 

[The Baker]

Have you put the three port valve or the two 2port valves in the open position before re-filling, also the pump probably has a bleed screw on the can shaped bit, and there is likely to bleed screw thing to enable you to bleed air out of the DHW side of the system.

If you make sure the valve/valves are open you could drain the system and then refill it with some one standing at each rad ready tighten up the bleed screw when that rad fills up.

Its not such a daft idea as it may first appear.

Tim

PS have just seen Micks post "sounds like cold feed block or at least very restricted, probably where c/f joins system." which is a definite possibility.

 

[Agile]

IF the cold feed is not restricted then put the system on CH only and turn all but one rads off and run for a few minutes with the pump on "3.

More the open rad along until the flow has been concentrated through each rad in turn.

Last put on HW only and run for a few minutes opening any air bleed screws at the cylinder.

Then return the system to normal with pump on "2" and it should work.

If the feed pipe is blocked then it will mean cutting pipes out. You can usually sense the blockage with a powerful magnet.

Tony

 

[gbo]

The system uses a mid position valve. Can you confirm what the open position in this would be?

When going through the one radiator at a time should the boiler be off?

I have bled the pump through the bled screw but not the DHW side i will give that a try.

Thanks

 

[gas4you]

Attach a hose to a drain point and open it.

Whilst the water is draining out look in your loft at the small F&E tank.

This should be filling as you are draining. If it isn't, or is only trickling out of the ball valve, then you have a cold feed full/partial blockage.

 

[Agile]

The system uses a mid position valve. Can you confirm what the open position in this would be?

When going through the one radiator at a time should the boiler be off?

Thanks

If its a Honeywell mid position the both open is with the manual lever latched. But my advice did not involve using that feature.

If the feed is not blocked as tested according to Dave's advice above the running each rad on its own is with the pump on but it does not matter much if the boiler is on or off.

Tony

 

[gbo]

Hi thanks for the tips Ive been away for a few days.

Tried CH on turned off rads then back on one by one bleeding each. The water spurted for all rads except one did not spurt quite the same as others. Then bled DHW side. Turned on boiler it fired, flow pipe from boiler became hot but return pipe cold. Rads did not heat up. Boiler cut off but the overheat did not seem to trip just stopped firing after about 5 mins.

Any ideas?

Could it be excessive sludge in the system?Or something more serious?

 

[spacethegas]

Attach a hose to a drain point and open it.

Whilst the water is draining out look in your loft at the small F&E tank.

This should be filling as you are draining. If it isn't, or is only trickling out of the ball valve, then you have a cold feed full/partial blockage.

have you tried gas4you advise yet ?

 

[gbo]

Hi. Yes I have checked the C/F and F/E tank and they are ok. The water fills the tank at a decent flow rate with the drain cock open.

I have since drained the whole system again with all rad valves open and bleed screws open to ensure it is completely empty. From this point what is the best way of ensuring no air gets back in when refilling?

 

[spacethegas]

its already full of air so none will get back in.
close all vents.
make sure programmer/spur is switched off.
manually open diverter valve.ie slide lever across & lift up, allow spring to return it to the locked position.
bleed all rads & any manual air vents. it does not matter in which order.
make sure any automatic air vent caps are open.
when you get water stop. forget about spurts.
bleed pump if necessary.
wait for f&e tank to stop filling.
run for 5 min or so untill gurgling calmes down.
turn off again.
make sure diverter is still manually open.
vent rads etc again.
carry on in this sort of fashion.
see how it goes.

do not vent system whilt pump is running.

 

[gbo]

Hi Guys. Thanks for the advice.

After many hours of bleeding rads manual air vent etc i managed to get the system just about there. Except there was one rad with a cool spot in middle bottom and one with half the rad cool. So i tried more bleeding etc and to my dismay the manual bled screw will now not close properly. It looks like the soldered part has came loose with all the opening and closing. What is the best way to fix this?

Thanks

 

[spacethegas]

oh dear...flood?
drain down & resolder or better still replace with aav.