Drained central heating now getting strange noise

[SkipFeeney]

Hi,

I drained my central heating and water system to move a radiator. Since filling it back up, its not quite working 100% and there are some strange gurgling and humming noises. This is what i did, have i missed anything:

1) Turned boiler off
2) Turned water off
3) Drained Hot and Cold water
4) Drained CH

- Moved the pipe work as required.

5) Turned on cold water (waited 15 mins)
6) Turned boiler back on
7) Bled all radiators and turned he air valve (in 3rd picture)
7) Turned heating on (waited 15 mins)

Any idea what it could be? I have a Potterton Netaheat 50e. All the rads soon filled up ok and the water tank fills up so don't think it is the cold feed.

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• SkipFeeney
• 20 Apr 2014
• 1

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• SkipFeeney
• 20 Apr 2014
• 1

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• SkipFeeney
• 20 Apr 2014
• 1

 

[Whitespirit66]

When you drained and refilled the ch system, did you latch the lever open on the motorised valve?

After refilling system, did you bleed the pump?

Could be air working it's way around and an unbled pump. The 'not quite working 100 percent' could be airlocks.

 

[AngelesPlumbing]

Im not quite sure, it might be debris in the system that has been disturbed and stuck in the system, if you have time buy sentinel x8000 and put it in the system and you can see at the bottle how much dosage you need, turn heating on full rate for 1 or more then drain the system while is hot. Dont forget override the motorised valve while draining. Hope it helps

 

[ALCPlumbing]

You will find after completely draining down and refilling that there will be pockets of air in the system. You just need to let it run normally and when the system is cold and settled, bleed all the radiators. If you have any automatic air vents make sure the cap is open enough to vent air. If you have any manual vents make sure you vent these.
It should sort itself out soon.

 

[stardanny]

Switch it off and let it settle for a while, that will move air to the highest point where it can be bled.

Switch hot water only on the programmer to get the pump and boiler going, it will shift air to boiler vent and in time clear itself.

Once it is quiet down, turn hot water off and turn heating on, again boiler and pump going, it will shift air to radiators to be bled and boiler vent, it will clear up in time.

It will take time.

Daniel.

 

[SkipFeeney]

When you drained and refilled the ch system, did you latch the lever open on the motorised valve?

After refilling system, did you bleed the pump?

Could be air working it's way around and an unbled pump. The 'not quite working 100 percent' could be airlocks.

Motorised valve - Arrgh i missed that, didn't realise i had to do it. Which lever is it, is the one here:

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• SkipFeeney
• 20 Apr 2014
• 1

Do i just move it to the right, refill then move to left? There is no markings on the valve.

Also how do i bleed the pump?

I have just noticed that it only seems to make a noise when hot water only is on.

Thanks for your help.

 

[Whitespirit66]

The valve needs to be latched in mid-position before draining and left in this position until the system has been refilled. Doing this means that both ports in the valve (hw and ch) are open, and the system will drain completely and refill properly. To do this, the black lever has to be slid to the right and latched in the cutout so that lever stays there. Also, when a system has been drained, the air that gets trapped in pump needs to be purged after refilling. Air in pump can make it run noisily.

You should;

Turn ch off and leave valve latched for 10 mins to see if any more water enters system from header tank. Unlikely by now, but just in case.

Then bleed pump by loosening large screw in middle until a trickle of water starts running out of screw. Then tighten screw.

Turn on heating. Any rads still not working because of trapped air will come back on eventually. You could turn off some working rads to force the airlock out.

Bleed rads when system all OK.