Can't bleed radiators

Finchy2018

Our house is getting progressively colder. The rads are just not heating.

My issue is, I can't for the life of me bleed the radiators, the key won't fit at all, is this supposed to be a universal key? I did read that you could use a flat screwdriver no some, but this doesn't appear to be an option either. Any tips ?

tacpot12

The key is pretty much universal, but some older radiators have a slightly smaller (4.8mm vs. the 5mm standard) on the back of the radiator where it is difficult to get a key onto the bleed valve.

Search eBay or Amazon for "rear access radiator key" if this is the problem.

If the valve heads are slightly rounded and are the older 4.8mm (3/16") pattern, the now standard 5mm key can struggle to turn them. You need a 4.8mm clock key (sometimes described as a No 12 key, but less commonly as a No 10 key).

I thought I had a similar problem recently with the drain valves on some old Pegler Terrier lockshield valves and nearly bought one of these keys: https://www.cousinsuk.com/product/traditional-steel

In the end it wasn't that they were rounded, just that they were done up so tight the cheap radiator key I had was deforming and eventually broke. I found this out when I got a good quality 5mm key from a plumbers merchants and this worked on all the valves.

Frank99

tacpot12 wrote: »

The key is pretty much universal, but some older radiators have a slightly smaller (4.8mm vs. the 5mm standard) on the back of the radiator where it is difficult to get a key onto the bleed valve.

Search eBay or Amazon for "rear access radiator key" if this is the problem.

If the valve heads are slightly rounded and are the older 4.8mm (3/16") pattern, the now standard 5mm key can struggle to turn them. You need a 4.8mm clock key (sometimes described as a No 12 key, but less commonly as a No 10 key).

I thought I had a similar problem recently with the drain valves on some old Pegler Terrier lockshield valves and nearly bought one of these keys: https://www.cousinsuk.com/product/traditional-steel

In the end it wasn't that they were rounded, just that they were done up so tight the cheap radiator key I had was deforming and eventually broke. I found this out when I got a good quality 5mm key from a plumbers merchants and this worked on all the valves.

Any good?

https://www.screwfix.com/p/plumbing-tools-by-rothenberger-4-way-radiator-services-cabinet-key/84379?tc=GC9&ds_kid=92700022855719858&ds_rl=1241687&ds_rl=1245250&ds_rl=1244066&ds_rl=1249796&ds_rl=1245250&ds_rl=1249481&gclid=EAIaIQobChMIg4OivP6-5gIVQuDtCh2KHwA-EAQYBSABEgLJ7_D_BwE&gclsrc=aw.ds#product_additional_details_container

FreeBear

tacpot12 wrote: »

The key is pretty much universal, but some older radiators have a slightly smaller (4.8mm vs. the 5mm standard) on the back of the radiator where it is difficult to get a key onto the bleed valve.

Got a similar problem with Kudox radiators - The brass key I have is slightly too small for the bleed nipples. The bit of plastic that Kudox supply is crap and breaks on the first use... Fortunately, the nipple has a slot so that a screwdriver can be used.

OP - Do you know what brand the radiators are ?
If you have a key that fits, and you still struggle to turn them, depending on access, give the head a little tap with a small hammer and/or a squirt of Plusgas penetrating oil.

JimmyChanga

Get the 4 way key from Toolstation or the like. Does rads and gas meter boxes etc. Made of metal and the 4 way cross provides good leverage so you don't break your fingers.

Finchy2018

Thanks guys - I have that four way tool - and still no luck. I can't see obviously what make the rads are.

I might try using a hammer - I suspect they are just all tight, but I have tried 3 rads on the ground floor and had no luck with any of them. Hoping it's not that I just need to go to the gym more to build some muscles!

thorganby

Finchy2018 wrote: »

Our house is getting progressively colder. The rads are just not heating.

My issue is, I can't for the life of me bleed the radiators, the key won't fit at all, is this supposed to be a universal key? I did read that you could use a flat screwdriver no some, but this doesn't appear to be an option either. Any tips ?

Everybody seems to be missing the elephant in the room!

A bit of air in the radiators will not prevent all of the radiators heating up.

They won't all need bleeding, any air will collect at the highest point in the system, not in "rads on the ground floor"

You need to logically check the system e.g. boiler, pump and follow the heat along the pipework, if any is produced.

Finchy2018

thorganby wrote: »

Everybody seems to be missing the elephant in the room!

A bit of air in the radiators will not prevent all of the radiators heating up.

They won't all need bleeding, any air will collect at the highest point in the system, not in "rads on the ground floor"

You need to logically check the system e.g. boiler, pump and follow the heat along the pipework, if any is produced.

I did read that - but everything says bleed rads first then problem solve further. the boiler sounds like its working - upstairs rad in bathroom gets warm but not hot the pipes are all warm, not hot mind you.

bertiewhite

thorganby wrote: »

They won't all need bleeding, any air will collect at the highest point in the system, not in "rads on the ground floor"

Of course ground floor radiators can trap air, especially if both connections are at the bottom.

I must admit though, the course of action does depend whether none of the radiators are heating whatsoever or if they are "just luke warm at the top".


OP - have your got TRV's fitted to your rads? If so, they could be stuck in after a period of non-use.

akira181

If the system is at sufficient pressure and there's air in it, then only the top of the rads will be cold, the rest of it should still warm up. If the bottom is cold and the top hot, then you got sludge in the rads. Also, the pipes going to the rads should be hot to the touch. If they're not, check the pipes leaving the boiler. If they're hot, then there's possibly a blockage somewhere. If they're cold, you got issues with the boiler.

Finchy2018

So tops of all dad's downstairs cold. The whole rad in both rooms are lukewarm as are pipes. I have tried upping temp on the boiler but it doesn't seem to want to budge.