Heating System Problem?

dickibobboy

Hi, following me posting this thread

http://forums.moneysavingexpert.com/showthread.html?t=1491393

I tried the radiator the day after when it was turned on and yes, it is cold at the top and *warm* at the bottom, where as the rest are hot to touch around the house. This radiator is the only one that is higher than the boiler.

I turned off the heating and did the ground floor radiators, water straight away no air. Same for the first floor. Straight up to the attic one, a little bit of air then it stops and no water or anything (i have tried bleeding it around 4 times over the last couple of days trying different things and got a small amount of air).

I am now unsure what the problem could be. The rest of the heating system is fine and the hotwater runs good although does often get air into the pipes as sometimes when turning the hot tap on in the bathroom it can 'spit' at you and then flow normal.


I checked the boiler and the manual and it explains that the pressure should be at minimum of 1 bar and maximum of 1.5 bars and 1 for every meter the highest radiator is, so for my case should be 1.3ish. The boilder is reading it as 0. Nothing, no movement, same with the heating turned on.

Although the rest of the system works fine apart from the one radiator (in the coldest room in the house!) and don't really want to fill the pressure up only to find it causes another problem elsewhere.

Thank You.

MX5huggy

You need pressure in they system as you say the manual says over 1.0 there should be a "tap" near the bottom of the boiler to fill the system with. If you have no pressure the air wont come out as they system is at the same pressure as the outside.

Adding pressure to the system may casue a leak but you have to do it

Note I presume you have a combi boiler with no header tank.

dickibobboy

Yes sorry, a Combi boiler.

I have taken a look at the tap and the manual and now know what to do to get the pressure up. Although when i do, will it make my taps have more pressure as they are already at a 'good' one.

Thanks.

ariba10

The pressure in the boiler will have no effect on your taps.

They are two independent systems.

dickibobboy

Thank You,

I started off by filling it up to .05 and then bleeding the radiator. Alot more air came out and when i went back to the boiler it was back on 0. I then put it up to 1 bar and did the radiator again, quite alot of air came out again and stopped. I went back and again it was back to 0. I then topped it back up to just over 1 and went back up, after a second i had water coming out!

Made sure the pressure was just over 1 bar and turned the heating back on. I could now feel the heat. It was hot to touch all over, its been so long like it has and with now 30 minutes of it being on upon entering the room i can feel the warmth that it did not get before.
Hopefully will not have to buy a heater for the room now! :cheers:

One thing i am a little worried about though. After 15minutes of the heating being on i checked the pressure and it had gone up to 2! I turned the heating down and went to look through the manual. When i went back to look it had dropped a little and was around 1.5 (max it should be at really) so i decied to leave it. While looking at the boiler the heating kicked in and started up, i saw the pressure rise a little back up to around 2.

Any ideas.

I will look at using the saftey valve to take some water out of it tomorrow although its a little hard to get to. so hopefully i will not have to.

One more question. If i was to just bleed some water from the radiator would that have the same effect and lower the pressure?

ariba10

You should take the pressure reading when the boiler is cold.

As the water warms up it expands and the pressure increases, that is as it should be.

If it gets above about 3 Barr the safety valve comes into operation and vents the water to the outside via the overflow pipe.

There is little for you to worry about.

ariba10

To answer your last question that I missed.

You can lower the pressure via the bleed nipple.

dickibobboy

Thank You for your reply.

I will keep an eye on it see what its like in the morning when it is fully cold.

I did get the pressure to around 1.2 when it was warm and turned off. Soon as i put the heating on it went up.

Aslong as i'm not going to wake up to water all over i will leave it for now

Thanks.

dickibobboy

Well up on checking tomorrow morning when the heating was on it was around 1.3, upon checking it around 5pm it was at 0, this is when the heating was off (not 100% cold though)

Maybe a small leak?

ariba10

How old and what make is your boiler?

dickibobboy

Not sure about the age of the boiler, we moved in 7 years ago and it was already there..
The boiler is 'Vokera' 'The Linea Range'