One radiator not heating up

[Ashgvas]

Hi All,

We renovated our house in 2019 and put in completely new plumbing system and piping including new boiler and 9 radiators. Off those, there is one radiator in the living room which does not heat up at all. I have tried balancing myself and also had a professional come in to balance it but the radiator just won't warm up like the other 8 do. It is possible it may be the last one in the flow, but I have tried turning off all other rads and yet it refuses to heat up.

I have checked the lockshield valve and they are both fully on. One valve (which I assume is the flow) is burning hot, while the other valve remains cold.

My question is could this be a case of blockage in the radiator? If so, do I need to do a complete power flush or simply flushing the radiator in question would be enough? Any experts out there who can help? (Note: I am not a professional and will need professional help to get either of the tasks done). The original installers have suggested doing a complete power flush (they are charging £800 for that), while another one suggested flushing only the radiator in question. Any advise and pointers on this will be greatly appreciated!

many thanks,
Ash

 

[CBW]

Is it new pipework and radiator? Are both pipes the flow pipe?

 

[Ashgvas]

Yes new pipework and new radiator. The radiator we have is a new cast iron radiator. There is no exposed pipes as such, but there are two lockshield valves. I think one is flow, other is return, as one gets hot straightaway, while the other remains cold.. and slowly gets lukewarm at best.

Thanks!

 

[Dereekoo]

Close valves, take off radiator, open each valve individually and see if flow comes out (good if you can have hosepipe and connecter to discharge outside). If flows ok take rad outside and flush. If not, power flush on the agenda

 

[Harry Bloomfield]

Yes new pipework and new radiator. The radiator we have is a new cast iron radiator.

Why would a new radiator and new pipework, be in need of a powerflush, or a flush at all? Did the radiator ever work?

 

[Ashgvas]

Close valves, take off radiator, open each valve individually and see if flow comes out (good if you can have hosepipe and connecter to discharge outside). If flows ok take rad outside and flush. If not, power flush on the agenda

Thank you. Actually the plumber came over a few weeks ago and did that. He only drained the rad - and showed me darkish water being drained out. I asked him if he could flush the radiator (And for whatever reason, he said he couldnt). Instead he suggested a complete power flush - which they are charging £800 for. So I am looking for a second opinion - do I need a full power flush, if the issue is with only one rad?

Does it make sense to flush the radiator which has the issue and see if it fixes? Or is it recommended to power flush the whole system straightaway?

 

[Ashgvas]

Why would a new radiator and new pipework, be in need of a powerflush, or a flush at all? Did the radiator ever work?

Yes - this is the biggest question / concern I have. The radiator had always been slow to warm up. Initially it was attributed to being "last on the circuit", but I think it has progressively gotten worse.

When I called the installers back, they claimed that water is very hard, and the cast iron radiators from Victoria Plumbing are a it and a miss, and can accumulate sludge. To his credit, he did disconnect the rad and showed me darkish water from the rad - but then he also didnt flush the radiator - instead suggested power flushing the whole system - so I am not sure about his advice. Especially as he is quoting £800 to flush the the whole system (fitted in 2019)

 

[Dereekoo]

Just clean out the one rad with hose pipe and confirm flow goes through in the 1st instance.Have you a magnaclean on the system.

 

[Ashgvas]

Just clean out the one rad with hose pipe and confirm flow goes through in the 1st instance.Have you a magnaclean on the system.

Thank you! No, we dont have Magnaclean on the system. We did put inhibitor liquid in at the last service (18 months ago).

QQ - do you think that flushing a radiator can be done as DIY through tutorial? I am not really an expert... but can do a bit of DIY?

 

[Harry Bloomfield]

QQ - do you think that flushing a radiator can be done as DIY through tutorial? I am not really an expert... but can do a bit of DIY?

Yes! But rather than just the one radiator, flush the entire system out thoroughly, until it runs clear, then add inhibitor yourself.

You can manage it with garden hose pipes.

 

[CBW]

Why would a new radiator and new pipework, be in need of a powerflush, or a flush at all?

New systems require a flush to remove debris and flux residue, albeit usually a hot and cold flush.

 

[CBW]

@Ashgvas - can you check the manufacturers instructions as I believe some modern radiators have baffles in them, make sure it’s fitted in the correct orientation.

 

[Harry Bloomfield]

New systems require a flush to remove debris and flux residue, albeit usually a hot and cold flush.

I was referring to it needing a powerflush now, so soon after original installation was completed - assuming it has had inhibitor put it, as it should. My own system is 40 years since it was installed - drain my system and what comes out is completely clear.

 

[Dereekoo]

Thank you! No, we dont have Magnaclean on the system. We did put inhibitor liquid in at the last service (18 months ago).

QQ - do you think that flushing a radiator can be done as DIY through tutorial? I am not really an expert... but can do a bit of DIY?

No good trying to flush one rad insitu, it needs to be taken off and done in isolation in the garden. Easy enough DIY as long as your isolating valves work and you can lift/remove the rad( extra hands make it easier) Hopefully should be some info on Utube. Good luck

 

[JohnD]

My own system is 40 years since it was installed - drain my system and what comes out is completely clear.

Sometimes that is because all the sludge and sediment has settled to the bottom of the pipes, radiators and boiler.

Put some X400 in and I bet it will go black.