Replacing radiator, top up/system pressure?

[MShield9]

Hi All,

I appreciate there are numerous similar posts but I'm look for clarification to judge whether I should try to replace radiator or have a plumber come out.

I have an Ideal Logic Heat 12 boiler and Tribune HE cylinder, circuit for hot water and 2 circuits for heating as I understand it. I've been trying to get my head around it a bit more but there's so much differing info out there. I'll attached some pics.

I am looking to install a new towel rail radiator in our bathroom. So far I have taken the old one off, closed the TRV and lockshield to do so and have left them be. Needed to get that off to do some prep on the wall.

I've read I could open up either side of the pipework one side at time? I'd need to do some re-working of the pipes to feed the new style radiator neatly. If that is possible and I managed to re-work and put new valves on, get the new radiator up - what then? How would I fill it and maintain system pressure*

Many thanks in hope of some help

* On a related note, while trying to figure this out I was tempted to follow some guidance somewhere about topping up pressure and opened the black handled valve on the flex attached to the pressure gauge. This did cause an increase in the reading (was sitting at 0.5, just let it go slightly to see it work) but the valve then started dripping steadily. Is that just normal for a rarely used valve? I did get it to stop by putting it just a smidge from hard off.

 

[terryplumb]

You would need to drain the heating system if you are going to remove the radiator valves and alter their pipework.
If the valve on the filling loop leaks when operated it probably needs replacing, where exactly is the water leaking from ?
The filling loop is used to fill the system,and inhibitor should be added too.

 

[MShield9]

Glad I asked! I've read elsewhere if you only open the inlet/return one at a time you'll get a bit of water initially but not much and be able to work on it.

The water was a steady drip from where the black handle is attached to the valve, it was dripping pretty steadily, but stopped when I just nudged it a degree back towards open.

Is draining and refilling a big pain? Can't quite stomach the £180 I'm looking at to get someone out (one plumber as a bit cheaper but long wait).

 

[terryplumb]

If you depressurise the system,to quickly swap a valve for a new one,that's called snatching and pro plumbers do it all the time. However ,if you are going to work on the pipework it's best to drain out ,at least to a level lower than the pipework you intend to cut into / work on.
From your description the filling loop valve is leaking from its spindle ,and needs replacing.

 

[MShield9]

Not sure if I'm glad I touched it so I know there's an issue or if I wish I'd never touched it

Thanks for your input. Maybe just have to bite the bullet and get someone out, not sure how to go about draining the system so might be best to get someone who knows the score.

 

[terryplumb]

Entirely up to you ,but there is nothing complicated about draining a central heating system . As you were contemplating amending pipework I assume you have at least some plumbing skills ?

 

[MShield9]

Plumbing skills are in progress, developing for this particular job. Have capped off feeds to taps in the bathroom in question while changing sink and shower and such but not done anything anything on heading side other than closing these valves and taking the radiator off as above.

I can generally turn my hand to anything I can find a good guide for, but as there's a lot of variation in heating systems I'm struggling to be sure how to go about it. Every radiator in the house has a lockshield with what looks like a drain (attached), rather than one radiator somewhere which is identifiable as a drain point as described in many guides.

 

[terryplumb]

That is indeed a drain off ,and not unusual to have one on every ground floor radiator if pipework to each rad comes from above ( higher floor level) .