Bleeding after drain and new valves
- Thread starter Diyer22
- Start date
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Yes - too much pressure will just shoot water up the expansion pipe and into the tank.
John
John
Connect the garden hose to the drain cock.
Open the drain cock.
Open garden tap 1/4 of a turn.
Bleed nearest radiator, then go around the hose bleeding the rest.
Once complete go in the loft and check expansion tan is filling.
Turn off garden tap and close drain cock.
Turn on heating and check radiators for heat.
Also go into the air-in cupboard and check the copper pipe work where the cold feed from the expansion tank joins the rest of the pipework with a magnet.
Report back.
Andy
Open the drain cock.
Open garden tap 1/4 of a turn.
Bleed nearest radiator, then go around the hose bleeding the rest.
Once complete go in the loft and check expansion tan is filling.
Turn off garden tap and close drain cock.
Turn on heating and check radiators for heat.
Also go into the air-in cupboard and check the copper pipe work where the cold feed from the expansion tank joins the rest of the pipework with a magnet.
Report back.
Andy
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Unfortunately the cold feed to the system is under the floor boards somewhere so I cannot get to it.
That is why I was suggesting blocking them off and putting new pipes into the airing cupboard before the pump.
I will cross that bridge once I have got the system working.
Thank you.
That is why I was suggesting blocking them off and putting new pipes into the airing cupboard before the pump.
I will cross that bridge once I have got the system working.
Thank you.
So I will most likely do this on Friday as it is difficult to get into my sons bedroom to bleed the radiator when he is sleeping.
Could I create a loop fill system from the output of the tank, through a valve, into the vent pipe? This way, it should still be gravity fed, will still be metered by the ballcock, will vent back to tank when the system is full, and I can then turn off the valve when complete so it can become a vent pipe again.
Once again I have created a small diagram to show what I mean. The light blue line is the active line when filling via the vent pipe.
View media item 103314
Could I create a loop fill system from the output of the tank, through a valve, into the vent pipe? This way, it should still be gravity fed, will still be metered by the ballcock, will vent back to tank when the system is full, and I can then turn off the valve when complete so it can become a vent pipe again.
Once again I have created a small diagram to show what I mean. The light blue line is the active line when filling via the vent pipe.
View media item 103314
I think in theory this should be OK - after all, the expansion pipe and the cold feed are indirectly joined together.
The expansion pipe of course must never be obstructed in any way.
The water level in the expansion pipe is the same as the water level in the tank, and the expansion pipe is connected to the 'hot' side of the system.
The cold feed enters the system at a low point on the 'cool' side and on a well set up system the water levels shouldn't alter anyway. (Thinking aloud!)
Have you considered disconnecting the cold feed and attaching a wet vacuum cleaner to the end, with the intention of sucking the blockage through? You never know.....!
I would love a professional to step in here with their opinion.
John
The expansion pipe of course must never be obstructed in any way.
The water level in the expansion pipe is the same as the water level in the tank, and the expansion pipe is connected to the 'hot' side of the system.
The cold feed enters the system at a low point on the 'cool' side and on a well set up system the water levels shouldn't alter anyway. (Thinking aloud!)
Have you considered disconnecting the cold feed and attaching a wet vacuum cleaner to the end, with the intention of sucking the blockage through? You never know.....!
I would love a professional to step in here with their opinion.
John
Thank you for reassuring me that this should work.
I did think about connecting a wet vac to the cold feed at the tank and try to suck anything back out. For some stupid reason the cold feed and return seem to be under the floor near the boiler, not by the pump which is in the airing cupboard. It would have been significantly more accessible and a much shorter run of pipe work. That is why I am thinking in future to cap off the cold feed and return and plumb in new lines just before the pump.
I think I will try my idea because it is only a bit of extra pipework to have a system that is still governed by the tank water level, and will still allow the vent to work as intended once the system is full.
I did think about connecting a wet vac to the cold feed at the tank and try to suck anything back out. For some stupid reason the cold feed and return seem to be under the floor near the boiler, not by the pump which is in the airing cupboard. It would have been significantly more accessible and a much shorter run of pipe work. That is why I am thinking in future to cap off the cold feed and return and plumb in new lines just before the pump.
I think I will try my idea because it is only a bit of extra pipework to have a system that is still governed by the tank water level, and will still allow the vent to work as intended once the system is full.
So just a quick update as promised.
I tried to divert the feed and expansion tank through an isolation valve into the vent pipe in the hope to fill the system through the vent pipe. It did not work.
I then tried to back fill the system via the drain port above the boiler and that also did not work.
Finally I tried back filling the system via the point I drained from (in the lounge) and finally managed to get water into the system.
Bled all the radiators and had water coming out the overflow (from the tank to outside).
I now have hot water and heating at 6 of the 7 radiators.
I need to balance the system and hopefully that will get the final radiator working.
Next steps will be to put in a new feed and return to the airing cupboard and block off the two current pipes in the loft.
Is this the right or wrong thing to do?
Thank you all for your help so far.
I tried to divert the feed and expansion tank through an isolation valve into the vent pipe in the hope to fill the system through the vent pipe. It did not work.
I then tried to back fill the system via the drain port above the boiler and that also did not work.
Finally I tried back filling the system via the point I drained from (in the lounge) and finally managed to get water into the system.
Bled all the radiators and had water coming out the overflow (from the tank to outside).
I now have hot water and heating at 6 of the 7 radiators.
I need to balance the system and hopefully that will get the final radiator working.
Next steps will be to put in a new feed and return to the airing cupboard and block off the two current pipes in the loft.
Is this the right or wrong thing to do?
Thank you all for your help so far.
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The fact that you failed to fill the system via the vent pipe is a bit worrying. If I have understood your last post correctly ,you introduced water ,under mains pressure ,into the vent pipe .And this didn't work. How did you make the connection ?
If you used a fitting ,and a watertight connection between vent pipe and mains ,and water did not flow into the system ,that would be indicative of the vent pipe being blocked, and that could have very ,very ,serious consequences.
If you used a fitting ,and a watertight connection between vent pipe and mains ,and water did not flow into the system ,that would be indicative of the vent pipe being blocked, and that could have very ,very ,serious consequences.
When you refilled from the drain down point, water entered the system and filled the header tank via the vent pipe......sure enough, the tank overflowed when it was full. Its evident here that the expansion pipe is unblocked (thankfully ) and all seems well.
There's no need to replace this pipe, but for the system to be bled properly you will need to replace or unblock the supply pipe to the radiator circuit at some time.
John
) and all seems well.There's no need to replace this pipe, but for the system to be bled properly you will need to replace or unblock the supply pipe to the radiator circuit at some time.
John
No, I must have not been clear.
The system was fed from the tank through a valve into the vent pipe not mains pressure.
Also, when filling the system through the drain, water did vent back to tank and them overflowed through the correct pipe to outside the house.
So basically it is venting but not refilling via the feed pipe.
The system was fed from the tank through a valve into the vent pipe not mains pressure.
Also, when filling the system through the drain, water did vent back to tank and them overflowed through the correct pipe to outside the house.
So basically it is venting but not refilling via the feed pipe.
When you refilled from the drain down point, water entered the system and filled the header tank via the vent pipe......sure enough, the tank overflowed when it was full. Its evident here that the expansion pipe is unblocked (thankfully
There's no need to replace this pipe, but for the system to be bled properly you will need to replace or unblock the supply pipe to the radiator circuit at some time.
John
Thank you. My reasoning for replacing both the vent and feed is that they are supposed to be 150mm apart (Maximum) and I don't want to lift the floor, therefore by plumbing in new pipes to the pump, I can eliminate the old feed and vent pipes entirely.
Please correct me if I am wrong.
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Mains pressure introduced at ground floor drain point , and did you see water coming out of the vent into the f&e ,or are you assuming it did because the f&e overflowed ?
I hope I'm not losing the plot here but I'm sure the 22mm vent pipe was allowing the tank to fill, rather than the feed one......someone up in the loft to see would have been useful! The 'spout' of the vent pipe will be wet, though.....maybe that's a clue.
Once the system is full, water needs to enter the radiator circuit via the 15mm feed pipe - if no water can pass through it then the rads won't bleed.
Please let me emphasise - the vent pipe must remain clear and unobstructed at all times but I doubt if that one needs replacing.
John
Once the system is full, water needs to enter the radiator circuit via the 15mm feed pipe - if no water can pass through it then the rads won't bleed.
Please let me emphasise - the vent pipe must remain clear and unobstructed at all times but I doubt if that one needs replacing.
John
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