Heating issues

[Willknapo]

Hello folks.
Im having constant issues with my ch it's a good few years old now....definitely past its best
I would say.
Anyway I keep loosing pressure in my upstairs rads and I get air in them on a constant basis even after bleeding.
It's a oil fired boiler with 9 rads on the system with a header tank in the loft.
I've tried a whole host of things to sort this and I'm in the process of replacing the last old radiator with a new one. Also 2 of the rads in the living room don't get hot at all even though water is flowing through them normally.
Does any one have any ideas as to why it's loosing pressure and pulling in air?

 

[Willknapo]

Also 2 of the rads in the living room don't get hot at all even though water is flowing through them normally

 

[ShaunCorbs]

sounds like you have a slight leak on the return somewhere and how do you know waters going through the two rads in the living room?

 

[jtsplumbing]

Must be loosing water somewhere , if no water visible it's got to be under ground floor, are you sure system is filled from tank in loft ? as you mention loosing pressure, how do you fill system ??

 

[Willknapo]

I've had the rads off and turned on the valves and water comes out, and the rads fill up when put back on but they just dont heat up

 

[Willknapo]

I can't see any visible signs of a leak. To fill the system I have to let the header tank in the loft fill up

 

[Willknapo]

There Is a slight leak on 2 very old rad valves upstairs

 

[Riley]

So your heating system isn't pressurised?

 

[ShaunCorbs]

are the flow and return the right way round (if you have trvs ) in the living room best way to test take the trv head off and see if it gets warm

 

[ShaunCorbs]

So your heating system isn't pressurised?

no open vented mate

 

[jtsplumbing]

If system is fed by header tank, and upstairs radiators are emptying then water must be leaving system quicker that header tank can fill it up, when you say you have to let header tank fill up, are you turning off water supply to this tank ? and how big is it ?

 

[Willknapo]

There is no trvs just normal rad valves. The header tank must be between 5 and 8ltrs maybe more. The header tank tips itself up sometimes after bleeding but I've drained the system down in the past week to fit a new pump to the system

 

[Willknapo]

Sorry tops it's self up not tips

 

[Riley]

Did it work properly before?

 

[ShaunCorbs]

as above and sounds like an air lock (maybe)

 

[Willknapo]

It's had issues for quite a few years apparently

 

[Willknapo]

It has had this issue for a good few years

 

[Willknapo]

It's had this issue for a good few years

 

[jtsplumbing]

1. why drain system to change pump. 2. when you fitted new pump is it facing the right way ?

 

[Willknapo]

Had to drain the system because one of the shut off valves either side of the pump doesnt work anymore. And yes the pump is fitted the correct way