Bled 3 Radiators Now Central Heating Doesn't Work

fleetingmind

A few of my radiators in the upstairs of my house were hot at the bottom but cold at the top so I bled them to get them hot.

I thought the heating was on the timer and it had gone off. I then noticed that it was actually on 'ON' (So on 24hours) but was not working. I tried the usual on/off etc but it still doesn't work.

Any ideas?
I bled the radiators with the heating on which apparently I shouldn't have done.

I have a presure system with a Megaflow tank in the loft with the boiler and a presure ball thingy up there too!!

Ob with two young kids I'm keen to get this fixed asap.

Thanks for any advice.

Alias_Omega

How do you top up the heating system pressure after you have bled the system.?

fleetingmind

Alias_Omega wrote: »

How do you top up the heating system pressure after you have bled the system.?

Would not have a clue. My DIY skills stop with putting a picture hook up.

stolt

i'm no expert on these type of things but the when you bled the rads i'm assuming you have bled them until the water comes out? Perhaps there is a problem with the cold water tank that feeds the rads, will need to check there is water in there.

Alias_Omega

Ok,

The heating system will be pressured. So when you open the radiator bleed valve, you are using that pressure to force the air out. Once you have bled the air out/fluid, you will find that the pressure is now 0.4 bar (for example) and should be replenished to 1bar.

Usually under the combi boiler there is a link pipe, which looks like something like this..






This is used to reset the pressure.

Does it look like this.?

financequest

I bleed my radiators once a year. 1. Turn heating off. 2. Open all radiator taps/thermostatic-taps on full, this allows free movement of air throughout the system during the following actions. Bleed downstair radiators first, then upstairs. 3. Re-pressurise system as described in earlier post. 4. Set radiator tap/thermostatic-taps back to required positions. 5. Turn heating on to test. BTW, a common issue I found was sticking thermostatic taps. To cure, remove thermostatic tap, NOT the actual valve. Then work the valve plunger up and down a few times with pliers, then replace tap assembly.

hethmar

Gawd, I have always bled mine when the heating is on! Thanks for the tips.

financequest - we had a heating engineer in last year to quote on extending the system. While he was here I pointed out one radiator that had never worked and asked if he knew why. LOL, he did exactly what you said and since then the rad has worked.

Alias_Omega

financequest wrote: »

I bleed my radiators once a year. 1. Turn heating off. 2. Open all radiator taps/thermostatic-taps on full, this allows free movement of air throughout the system during the following actions. Bleed downstair radiators first, then upstairs. 3. Re-pressurise system as described in earlier post. 4. Set radiator tap/thermostatic-taps back to required positions. 5. Turn heating on to test. BTW, a common issue I found was sticking thermostatic taps. To cure, remove thermostatic tap, NOT the actual valve. Then work the valve plunger up and down a few times with pliers, then replace tap assembly.

I bleed in a different method..

1, ensure heating is off
2, ensure heating pressure is more than 1 bar
3, close all radiator valves

4, open up one valve on radiator
5, bleed radiator until no air
6, close valve
7, open other valve
8, bleed until no air
9, close valve
10, check boiler pressure and top up if needed

My method isolates all radiators and bleeds each supply & return leg in turn. Therefore any air is elimated and not allowed to pass from radiator to radiator.

Also, if you have a rad that cold, you can close one valve off and bleed it until the pipes / rad get warm. Close that valve and repeat on other side of system. This elimates any airlocks within that section of pipework as bleeding with them open will just draw from the other side with no airlock, be it the supply or return.

Thats if you catch me..

Points to note though..

The thermostatic rad valve is the return valve
The capped off valve is the supply valve
The supply valve is setup for the radiator to be balanced, so if you open and close it, ensure you note how many turns you have made to set it back up.

& im not a plumber, so my advice is not offical, just a method i use from thinking through of the plumbing of the heating system in my house. All radiators are supplied parrallel from the boiler, and not in series.

Alias

C_Mababejive

I've never bled mine...it doesnt need it.

hunnycat

we have one radiator in my sons room which even after being bled is still cold at the top and hot at the bottom. does anyone have any clues? The british gas guy bled all the radiators when he serviced the boiler which helped for a while.

We have a radiator in our room which is constantly off due to being behind some stuff just now could this be the cause?

Thanks

Canucklehead

Good morning: excellent heating FAQs are available here and here.

HTH

Canucklehead