Built up pressure-help

[maverick]

Recently i removed a radiator in my kitchen, and put a stop end on the pipe. i have a combi-closed heating system. since then the pressure in the system has been gradually rising from around 1.2 bar up to just under 2.
i have been frequently relieving the pressure, bleeding the othjer radiators.
Is there something else i need to do to stop this, would appreciate any help! as i thinking of replacing the radiators in the lounge with cast iron 'school Rads'.

 

[Softus]

Recently i removed a radiator in my kitchen, and put a stop end on the pipe. i have a combi-closed heating system. since then the pressure in the system has been gradually rising from around 1.2 bar up to just under 2.
i have been frequently relieving the pressure, bleeding the othjer radiators.
Is there something else i need to do to stop this, would appreciate any help! as i thinking of replacing the radiators in the lounge with cast iron 'school Rads'.

Presumably you have trapped some air in the system, which then heats up and thereby increases the pressure. Either that or the filling loop valve is letting by - do you disconnect the filling loop after using it as per the manufacturer's instructions?

 

[meldrew's_mate]

Softus' is the most likely fault, though it is also possible the secondary (DHW) heat exchanger on the combi is leaking mains water into the heating system. Try removing the filling loop before considering this one

 

[maverick]

thankyou for your expert knowledge and coming to my aid, although being a novice plumber i'm slightly lost by your reply.
I not sure what you mean by softus!?
Also i persume the filling loop, is the hose attachment (which is a flexi-pipe with an on-off valve) which feeds the boiler from the mains in-pipe.
Originally, after i had removed the radiator i used this to top up the system and increase the pressure lost.
I will carry on bleeding the rads, although don't think there can be much air left in the system by now.
Also if you think its a good idea maybe, i could disconnect one end of the flexi pipe to see if the shut off valve is operating properly.
Previous to me fiddling with the rads, the system was at a fairly constant pressure.
I would very much appreciate your reply or any other comments.
Many Thanks!
Maverick.

 

[Softus]

I not sure what you mean by softus!?

Softus is my moniker on this forum.

Also i persume the filling loop, is the hose attachment (which is a flexi-pipe with an on-off valve) which feeds the boiler from the mains in-pipe.

Correct.

Also if you think its a good idea maybe, i could disconnect one end of the flexi pipe to see if the shut off valve is operating properly.

...do you disconnect the filling loop after using it as per the manufacturer's instructions?

 

[maverick]

The 'filling loop' is and always has been permanently fixed to the water mains in-pipe by a T junction, supplying the boiler. Its located underneath the boiler, amongst a tangle of pipe work. The only possible way to removed it, would be to undo the compression nuts. At the moment the filling loop is turned off.
I haven't read the manufacturers instructinos as i did'nt think it would be a problem removing one radiator.
I've had i another go at bleeding the rads and removed some more air, hopefully it will sort the pressure issue.
Many thanks for your swift reply. My plumber is always unattainable and i've given up trying to get him round!

 

[Softus]

At the moment the filling loop is turned off.

It may appear to be turned off, but it has yet to be shown that the valve is working as intended.

I haven't read the manufacturers instructinos...

Generally, these will state that the filling loop is to be disconnected after each top-up. The purpose of disconnection is to prevent backflow into the mains (if the valve failed and the mains pressure dropped below that of your system). The braided hose commonly used for this function has at least one plastic wing nut that you can undo by hand, but if you need to undo some brass nuts then you need to use a spanner or wrench.

 

[maverick]

Thanks, i'll see if the pressure has stabilized by the weekend, if not try removing the loop.
Do you do house calls!?
I have another problem, where the hot water will run hot then go cold, and continue to change.
My unattainable plumber checked the diaphragm which was working and said it was another thing wrong. thats the last i saw of him!

 

[Softus]

Thanks, i'll see if the pressure has stabilized by the weekend, if not try removing the loop.
Do you do house calls!?
I have another problem, where the hot water will run hot then go cold, and continue to change.
My unattainable plumber checked the diaphragm which was working and said it was another thing wrong. thats the last i saw of him!

Well I do, but we don't live near each other!

My advice to you would be to find another heating engineer in your locality. Most people ask neighbours / friends / colleagues for a recommendation. Or you could try the APHC web site and use the "Find a Plumber" section

In the meantime, do you see a light and/or hear a click (from the boiler) when you run a hot tap? If not then the boiler might not be detecting the flow of water, and would not heat it up.

Another good indication of detection of flow is that the burners fire up.

A common cause of your symptoms is a faulty and/or sticking divertor valve.

What is the make and model of your boiler?

 

[maverick]

The boiler is a Worcester 7??, i'm not at home at the mo.
The boiler does click and the burners fire up, but not sure if they stay on for the duration of the tap running.
Would that suggest a diverter valve problem?
If so could you give me a ball park figure for replacement/fitting?

 

[Softus]

The boiler is a Worcester 7??, i'm not at home at the mo.
The boiler does click and the burners fire up, but not sure if they stay on for the duration of the tap running.
Would that suggest a diverter valve problem?

Not enough information to say - sorry.

If so could you give me a ball park figure for replacement/fitting?

I would charge for a two-hour callout, plus parts. I would be surprised if the total came to more than £150, but other than that you'll need to get the problem properly diagnosed instead of replacing parts willy-nilly.

 

[maverick]

Once again many thanks for your advice, i'll leave you in peace now.
Its very re-asuring knowing some one out there cares about my plumbing problems!?
Don't get much support from the missus.
M