2 upstairs radiators need bleeding everyday

[Jonathan Reid]

Open vented system
2 upstairs radiators need bleeding everyday
First tried turning pump speed down from 3 to 1, but problem persists.
Any suggestions would be appreciated.

 

[Rob Foster]

When you bleed the system what colour is the water, especially the water from the good rads not the naughty ones.
This might indicate wether you have a leak. Is the f & e tank topping itself up ? tie ball up and see if water level drops over a day, few days or week plus. Presume no signs of a water leak . let us know others might have an alternative idea but this will clear some stuff out of the way. Rob Foster aka centralheatking and have you bunged any inhibitor in ...if so which

 

[king of pipes]

Post a picture of your pump cold feed and vent pipework usually this would be in the airing cupboard, your cold feed could be blocked ? is there water in the feed and expansion tank is it dirty in there maybe best to have a service call from a GSI to find the problem. Kop

 

[Jonathan Reid]

Many thanks for respective replies.
Water from good radiators is clear and there is no evidence of leaks anywhere.

There is water in the f&e tank but it is quite dirty and probably needs a good clean.

View attachment 20190113_081416.jpg

 

[Rob Foster]

ok, brown water would have inducated fresh water being fed into system regular. you have a filter ok. now tie up the ball valve on f & e tank ...the little one not the big one and see if the water level goes down...use a stick and mark it..check in a day, few days and week . and see whom else has ideas as they wake up. Rob Foster aka centralheatking

 

[king of pipes]

Can you tell me where the circled pipe goes please you have had some work done on the system is this a problem since then ? What does the lever valve isolate . Kop

 

[Jonathan Reid]

The circled pipes goes into the loft and have traced it going in to the base of the f&e tank. The isolation valve is for shower that was installed 3 years ago.
The problem with the air locking only started recently.

 

[Jonathan Reid]

Hi Rob, with regards to the movement of water in the f&e tank, if it was free of gunge and blockages would the water level rise when the heating is on and fall when the heating is off, or the other way round?

 

[king of pipes]

If the cold feed is on the live side of the pump then that's your problem . Kop

 

[Jonathan Reid]

Hi Kop, its an interesting theory and one which I will pursue further. It looks like the piping has always been configured that way. Does this mean the pump (fitted 2 years ago) is the wrong way round? Why would only 2 radiators be affected?

 

[king of pipes]

I would say your system is piped wrong see attached diagram circled is the correct position for the cold feed and vent in the neutral zone before the pump . Kop

 

[Aire]

Can you tell us which way the pump is flowing? From the pic it looks like it's pumping upwards but the installer may have flipped the pump head 180°. There will be an arrow on the side of the pump body to show direction of flow.

 

[Jonathan Reid]

Arrows are pointing downwards on the sides of the pump.

 

[Rob Foster]

Hi Rob, with regards to the movement of water in the f&e tank, if it was free of gunge and blockages would the water level rise when the heating is on and fall when the heating is off, or the other way round?

it might well rise or fall depending on the problem but really should be static. my concern is if it was all dandy why a recent problem, have you been playing with the pump speed ? or bunged any stuff in
chking

 

[Jonathan Reid]

Oh no. Rads started to play up so it was suggested to reduce pump speed from 3 to 2. No difference resulted so reduced the speed down to 1. Again no difference. Pump speed remains on 2 as all radiators warm up consistently throughout the house. Its just that 2 of them keep getting air in them.

 

[king of pipes]

Where is the vent for the system you could be pulling air in? it's the pipe that goes up and over the smallet tank in the loft . Kop

 

[Rob Foster]

ok , I am with the boys tomorrow at 7.00, central liverpool as its a new high rise start for a cuppa and will pose the problem, boys ! they are all over 6o been round the block , the world and most started at Cammel Laird in the diesel subs .lets see
chking

 

[Aire]

When your bleeding your rads, are you bleeding them when the pumps off or when the pumps running?

 

[Jonathan Reid]

Tried bleeding with pump on and off. Does it make a difference?

 

[king of pipes]

Better to do it with the heating off bud you found the vent ? a post picture please . Kop

 

[Aire]

Post a pic of the vent as kop suggests, although if this is a relativly new issue i cant see that been the cause, but we need to be thorough to best advise you. Couple more questions. How long has this issue been going on for? Has the system recently been drained down? Are you removing a consistent amount of air daily or does it vary, is It getting worse/better. Apart from the air, does the system run ok and when was the last time the filter above the pump cleaned out?

 

[Jonathan Reid]

Not sure if this picture helps. There is a pipe that goes down into the lid of the f&e tank. Followed down into airing cupboard. 2nd pipe from right in my earlier photo.

 

[Jonathan Reid]

First noticed issue in November 2018
New filter installed April 2018 and has not been cleaned since.
System has not been drained down recently.
System runs ok as far as I can tell. Pump runs quietly. All 13 radiators (7 up, 6 down) heat up consistently.
Pump running at speed 2.
Not entirely sure if its getting worse or not. I just became more aware of the problem.

 

[king of pipes]

Are we saying it's working like this then ?

 

[Jonathan Reid]

Yes thats correct.

 

[king of pipes]

Its as I said your introducing air into your system via the configuration of the filter , pump and vent pipework , the easy option is to connect the cold feed into the vent but if I were employed to sort it I would advise some changes to the pipework or even sealing the system if possible . Kop

 

[Jonathan Reid]

Thank you Kop, and everyone else, for your time today in replying to my post. I have learnt a lot today.

 

[Ken Barrow]

Hi. I have the same problem. The thing is - it’s a totally new system. I changed over from oil to gas and have all new system including pipe work and radiators. Old system stripped out. But from a few weeks after install, a few of the upstairs radiators need bleeding ever few weeks - probably every week if I checked. Usually the same 3 radiators upstairs but there’s 2 others which never need bleeding. They’re probably on a different set of pipework. So definitely not corrosion or gas or sludge buildup. I’ve checked on the internet and the only thing I can see that it might be, is that the pump is drawing air in. What I can’t understand is if there is a leak, why isn’t there water at the leak. Some say the leak isn’t big enough to let water out, but it is just enough to draw air in. The solution apparantly is to drain the whole system, and pressurise it to find out where the leak is. This involved some sort of liquid to detect the leak? Any info on how to do this and what is required or is it a specialised job. For info only, the system was installed by a large company who only installs central heating system and not done by a diy crew. Thanks ahead for any info.

 

[king of pipes]

Post a few pictures of your set up airing cupboard and boiler please??