Pressurised system help...please!

[bowfer]

Desperately looking for help, as SSE home services seem clueless.
We have a pressurised system using an old but reliable Ideal classic boiler.
Every now and then, I have to top up the pressure in a little red bottle in a downstairs cupboard.
However, for a while now, the fill loop doesn't seem to have been working.
I no longer feel water rushing into the red bottle, and I no longer see the pressure gauge going up.
Since these fill-loop problems, the central heating has been problematic.
Basically, the boiler and pump will keep going even through the controls say they should be off.
SSE home services have replaced the pump, a solenoid valve in the boiler and they attached a foot-pump device to a little bicycle-tyre style valve on the red bottle.
None of these seem to have stopped the problem, the boiler and pump were still running yesterday PM when they should have been off.
HELP PLEASE!!!

 

[GE Sonny]

The red bottle you talk off is the expansion vessel .what they have tried to do is repressurise it to try and solve the problem you've been having (losing water pressure). All this aside let's get down to the actual problem.
You've said you've been doing this for awhile, seeing that your system is old the first thing I would try is ;
Take a pz1 screwdriver and remove the black taps from the valve (s) try using an adjustable wrench or pliers to turn the spindle which operates the valve.
With frequent use this plastic taps wear and stop turning the valve, even when you think it is .
The red vessel may also have failed .
How often are / was you repressurising the syste

 

[bowfer]

Thanks for the reply.
When the fill loop worked, I was maybe having to top it up once or twice a month.
The thing is, I was never sure what figure it should have been showing on the gauge, or whether I should have been topping up hot or cold.
I used to keep the guage somewhere around the 1.5 to 2 bar level once was running.
Any less than that and I noticed I was having to bleed radiators from time to time.
Keeping it at that sort of pressure used to keep the bleeding away and gave us good heat and shower power.
I'm not really confident enough to muck about with the fill loop, just in case water starts going everywhere.

 

[gmartine]

When the system is cold the pressure should be set between 1-1.5 bar. Air trapped in your system is down to it being introduced everytime you repressurize not the pressure level itself.
IF you're having to continually fill up the EV (red thing) you have a leak, simple as. Get them back in tell them what you told us.

 

[bowfer]

How often should I top up?
What's the point at which you think there's a leak or not?

 

[bowfer]

Basically, I need to know what angle I should 'attack' SSE home services from.
I'm just amazed they've never noticed the fill loop issue themselves, it's not exactly encouraging.

 

[gmartine]

Losing pressure = leak
Having to top up = leak
Keep pressure above 1bar when cold, try not to refill when hot.

 

[GE Sonny]

Okay so check the tundish for signs on leaking, if this is dry and doesn't look like it's been leaking from any expansion / TnP relief valves .If no signs of leakage is present I would imagine youve got a leak somewhere .I would expect on a new system a few times in the first 6mts. Then maybe twice annually or when bleeding radiators or doing work.

The most common situation for this is that the expansion vessel has failed . When you first fire up the ch from cold, keep an eye on the pressure for 15 minutes and see if you can see a great rise (over 1 bar) if it rises more than a bar .Replace the expansion vessel .

Twice monthly seems to unfrequent for an expansion vessel fault and I'd say definitely points towards a small leak on the system.

Cold system pressure should be between 1-1.5bar .

 

[bowfer]

How do you go about tracing a leak in a pressurised system?
We have a few TRVs on radiators that ooze drops of black gunge onto the floor every now and then, would that be enough to reduce pressure?
I'm terrified of the word leak as it conjures up images of floorboards being ripped up etc.

 

[gmartine]

Yep small drips will depressurise the system.

Seems they also left the foot pump they used to inflate the EV on the system. If the pump has a pressure indicator leave it and take a reading when cold, it shouldn't be below 1bar.