Central Heating Nightmare - Air in System Daily

[dilalio]

My tuppence worth...

All new rads, boiler and pipework!
And the water is orange!
Something ain't right.
Is any of the pipework plastic?
Is it barrier pipe?
If not, it can draw oxygen in through the walls.
Fit the aerator first and see how things go.

 

[Elsa TLC]

Not read into this thread as its old and long.

Two questions.
● Are they designer Radiators?
● Are any of these Vertical Radiators?

 

[Cellophaneskies]

A light bulb went on when you mentioned possible DIY install, what's the betting it's a combi conversion, and Mr DIYer has got the pipework wrong under the floor, so that for example the flow is going down what was the old cylinder return, or something similar?
This happened to me when apprentice altered pipework in airing cupboard, despite me labelling pipes and tell him to connect pipe A to pipe B, and cap off pipe C. It worked, but badly, and displayed exactly the symptoms you have.

I don’t think that there’s any issue with pipework directions. The boiler has moved location entirely, originally ot was in a cupboard upstairs but now it’s downstairs in the hallway. I’ve had two or three companies look at this and no one has noticed any pipework direction issue.. pipework has all been seen visually, nothing is buried in concrete. The company that replaces pipes for me had full access to all pipes, all floorboards were removed above all pipework

I’d hope that any issue would have been spotted when most of the ‘backbone’ was re-piped.. I don’t think any old pipework was reused, most under floor upstairs is the plastic push fit type. Old pipework still remains with cut ends in place where they were too lazy to remove (and I have been too, but mostly due to inexperience.. next time I’m in there I’ll probably pull it out)

If I wanted to verify everything is correct. What would I do? I’m a bit unclear on the whole direction and return side of things.

 

[Cellophaneskies]

My tuppence worth...

All new rads, boiler and pipework!
And the water is orange!
Something ain't right.
Is any of the pipework plastic?
Is it barrier pipe?
If not, it can draw oxygen in through the walls.
Fit the aerator first and see how things go.

The stretch under the hallway floor upstairs is plastic push fit. It’s modern, installed by an established heating company. I don’t know if it is barrier, I only learned that this was a thing since last year! It is grey in colour if that helps at all.

I haven’t inspected water colour this year, I’ll see if it has changed since the flush. To confirm, it used to be a sort of coppery colour initially when bleeding but it does then run clear. When I’ve drained the system through a hose it does look clear. I saw the power flush water colour and it was quite grey and dark. Bloke said it was dirty but not astronomically so for the age of the install. I was a little surprised since this happened after several drains and all new pipes!

The plastic bowl I’ve used to bleed has gained a coppery coloured bottom, like the water dries out annd leaves a powder or solid coating, and it seems hydrophobic! The coppery colour residue makes water bead up on top of it. I’ll clean my bowl and see what colour is like now..

I’ll confirm the water colour thing as I may have not portrayed the situation correctly there.

 

[Cellophaneskies]

Not read into this thread as its old and long.

Two questions.
● Are they designer Radiators?
● Are any of these Vertical Radiators?

Most info is in my latest post. There is a diagram back there that may be useful.

One stelrad vertical rad next to the boiler. I’ve isolated this (turned off both valves) and the system behaviour does not change.

No designer. They are all boggo white panel radiators. Most are stelrad branded. One is ‘FIX’ which is an older one. And one is some other brand that escapes me right now )that’s what happens when you don’t specify brand to the installer I guess)


ORGINALLY when I moved in, there were three flat panel vertical radiators. I though the reason the house was cold was because they were crap, but in retrospect they were probably ok but I was experience the same problem I’m experiencing now.. poor performance unless you turn upstairs off and start the system with only two end rads active!

 

[dilalio]

ORGINALLY when I moved in, there were three flat panel vertical radiators. I though the reason the house was cold was because they were crap, but in retrospect they were probably ok but I was experience the same problem I’m experiencing now.. poor performance unless you turn upstairs off and start the system with only two end rads active!

What's the main issue here?
Air in the rads or rooms not getting to temp?
Boiling hot rads are not conducive to warm rooms.

Do some heat loss calcs and see if the rads are up to the task.

Is all the pipe plastic and what bore is it?

It's should say barrier pipe on it or have some markings regarding it's make up.

Pex-al-pex.

 

[Cellophaneskies]

Issue is- central heating only gets lukewarm and does not heat house unless I turn on radiators in a specific order. If I don’t touch it, the house doesn’t really feel heated. Or it takes hours. If I I play musical radiators, I’ll cook my arse off within 30 mins.

It’s also really noisy. Lots of gurgling and trickling. Not metal or expansion noises, but water noises. Every few days I can remove more air from the highest rad.

Ive done btu calcd before and all rads meet or exceed requirements. They’re quite big as I thought original issue was rads were too small!

Pipework is all copper from the boiler into the upstairs floor. Plastic ‘backbone’ along the stretch of the house (3,4m). Cooper pipework comes off that to each rad.

The ‘backbone’ from the boiler is 22mm I think (recently sized up from original 15mm), pipework to each rad is standard 15mm. When the pipework size was increased, no change to behaviour, but when the system is working well, things do seem hotter. But only after I play the game of turning things on in order

 

[dilalio]

Issue is- central heating only gets lukewarm and does not heat house unless I turn on radiators in a specific order. If I don’t touch it, the house doesn’t really feel heated. Or it takes hours. If I I play musical radiators, I’ll cook my arse off within 30 mins.

It’s also really noisy. Lots of gurgling and trickling. Not metal or expansion noises, but water noises. Every few days I can remove more air from the highest rad.

Ive done btu calcd before and all rads meet or exceed requirements. They’re quite big as I thought original issue was rads were too small!

Pipework is all copper from the boiler into the upstairs floor. Plastic ‘backbone’ along the stretch of the house (3,4m). Cooper pipework comes off that to each rad.

The ‘backbone’ from the boiler is 22mm I think (recently sized up from original 15mm), pipework to each rad is standard 15mm. When the pipework size was increased, no change to behaviour, but when the system is working well, things do seem hotter. But only after I play the game of turning things on in order

I'd love to be there and see it!
Do like a challenge that others haven't resolved xx

 

[HERTS P&D]

Do like a challenge that others haven't resolved xx

I also love a chalenge, not sure about the 2 kisses.



Andy

 

[Cellophaneskies]

I'd love to be there and see it!
Do like a challenge that others haven't resolved xx

I’m not loving living with it

Anyone I’ve spoken to is like ‘I’ve never seen this in my whole career’.

The smart thermostats are a total godsend. I can at least remotely fart about with which rads are running to coax it into order, will look into some automations.

This also demonstrates that the living rad thermostat climbs in temp very very slowly.. when I shut off other rads it will rocket up.

Once the worst offenders are nice and hot, the rest will cans turned on and they’re then nice and hot too. It’s not like turning them all on then reduces the output- it’s like once an ‘air block’ is cleared then every working works great!

 

[Harry Bloomfield]

Once the worst offenders are nice and hot, the rest will cans turned on and they’re then nice and hot too. It’s not like turning them all on then reduces the output- it’s like once an ‘air block’ is cleared then every working works great!

When you are struggling for heat, have you checked the flow and return temperatures, close to/at the boiler?

 

[Cellophaneskies]

When you are struggling for heat, have you checked the flow and return temperatures, close to/at the boiler?

I think I have in the past but the specifics escape me now. I can check again. I bet supply will be scolding hot and return all very very hot.

I don’t think the boiler is at fault as the issue was present with last boiler, and fidgeting with the rads seems to solve. But I can check this next time it happens..

 

[Harry Bloomfield]

I think I have in the past but the specifics escape me now. I can check again. I bet supply will be scolding hot and return all very very hot.

Do you perhaps have a bypass, which is opening too soon?

 

[Cellophaneskies]

Do you perhaps have a bypass, which is opening too soon?

Not fully sure what that is. There is only the boiler and circuit of rads. The other thing I forget to mention is that all my rads had locksheifl and thermostatic valve. On advice I removed the thermostatic valve from the bathroom rad so it has two locksheilds, so that there is always a path for water to take.

..no change in symptoms

 

[Harry Bloomfield]

Not fully sure what that is.

Idea of the bypass, is that as your TRV's are satisfied, so a flow through the boiler can be maintained to dissipate it's heat, there is a pipe link between flow and return, with an adjustable valve fitted, which opens at the set pressure.

On advice I removed the thermostatic valve from the bathroom rad so it has two locksheilds, so that there is always a path for water to take.

That, if correct, suggests that who ever mentioned you doing that - failed to find such a bypass valve on your system. It is usual advice, where there is no bypass, to suggest at least one radiator is not fitted with a TRV, so it can act as a bypass. Usually, the chosen radiator, is the one, in the same space as the room thermostat.