No filling loop and red expansion vessel installed. How to represurrize heating?

[Samsg30]

Hi,

I need bit of an advice about finding the filling loop in my heating system. Apologies for long description but thought to cover as much so relevant solutions can be suggested. I have spent endless hours searching internet including this forum and everywhere it is mentioned there must be two valves either near boiler or cylinder which is used to repressurize heating after draining and refilling but there isn't any installed at all near existing Megaflow by Heatrae Sadia or Glow worm Flexicom 30HX system.

Symptoms: -

My radiators were not getting hot enough after running heating for long time and called engineer who just bleeded few radiators and increased the pressure of heating system (which he found after a struggle as he said but I didn't see). He charged me £200 for 30 minutes job which is rip off.

Now within 2 weeks time, I got another plumber to change the radiator and two TRVs for which he had to drain whole heating system. He refilled the system by just turning the cold water supply only as there's no filling loop and pressure meter anywhere in the system to see what's happening. All radiators were bleeded twice and now no more air in any radiators.

When we turned the boiler on, it showed Fault 22 (i.e. low pressure error). We had to reset it twice before error disappeared automatically and heating started working but few radiators were not getting hot at all. Radiators were tested for air again it is fully filled with water as only cold water was coming out. Plumber advised to close some of the TRVs and locksheild which will push the water to other radiators, which did the trick indeed but except two radiators.

Problem: -
Out of 15 radiators, 2 of them are not getting hot at all and I am worried it is down to the heating pressure.

Help needed: -
Please if looking at the picture of cylinder, someone could advice if they notice anything which can be used to repressurize heating system. I know all the valves except red valve and the connection line it is attached to. Not sure if this can do any trick.
I have checked the Glow worm Flexicom 30hx system and there are no valves visible at all except one to switch off Gas supply and Megnaclean. I have not opened any face plate to check and won't do it at all as it is boiler system.

Thanks for your help and taking out time to read this.

 

[Nozzle]

That is either a relief valve or a bypass valve, what does the vertical pipework coming from the valve lead to a tunish/outside or the other side (suction) of the pump.

Nozzle

 

[picasso]

As the pipework goes upwards have you looked in the loft for expansion vessel and filling loop ?

 

[Nige F]

Hi,


**He refilled the system by just turning the cold water supply only** ........... All radiators were bleeded twice and now no more air in any radiators.

When we turned the boiler on, it showed Fault 22 (i.e. low pressure error). We had to reset it twice before error disappeared automatically and heating started working


Thanks for your help and taking out time to read this.

Maybe it's got a feed+ expansion tank - ie. open vented system

 

[dilalio]

As the pipework goes upwards have you looked in the loft for expansion vessel and filling loop ?

+1
You need to find that vessel!

 

[Samsg30]

That is either a relief valve or a bypass valve, what does the vertical pipework coming from the valve lead to a tunish/outside or the other side (suction) of the pump.

Nozzle

Pipe is coming from flow and going into return. Attaching picture

 

[Samsg30]

Maybe it's got a feed+ expansion tank - ie. open vented system

attaching picture of loft tank. There are no valves there. Pipes are coming from airing cupboard into loft. One of those pipe is main cold water.

 

[stardanny]

Your heating system is open vent. Check there is water in that black water tank, that is the feed and expansion tank.

Daniel.

 

[Samsg30]

Your heating system is open vent. Check there is water in that black water tank, that is the feed and expansion tank.

Daniel.

Ah.. so you mean... megaflo (by heatrae sadia) is sealed system which only provides hot water in taps and got inbuilt expansion vessel with T&R valve.. but the heating system is open vented as there's a tank in loft. Is this what supplies water in radiators? Also shouldn't I expect some sort of pressure meter and filling loop near loft tank or near boiler itself? But there isn't any at all. Attaching pictures of boiler and attic tank.

 

[stardanny]

Ah.. so you mean... megaflo (by heatrae sadia) is sealed system which only provides hot water in taps and got inbuilt expansion vessel with T&R valve.. but the heating system is open vented as there's a tank in loft. Is this what supplies water in radiators? Also shouldn't I expect some sort of pressure meter and filling loop near loft tank or near boiler itself? But there isn't any at all. Attaching pictures of boiler and attic tank.

No, your do not have a pressure gauge or filling loop. The tank do that, filling the heating via a ballvalve in the tank. You need to check there is water in it.

Daniel.

 

[Samsg30]

No, your do not have a pressure gauge or filling loop. The tank do that, filling the heating via a ballvalve in the tank. You need to check there is water in it.

Daniel.

so is pressure in heating system maintained by ball valve inside tank? I haven't checked the water in tank as it covered and secured with strings.
Can do that.. should I expect water there ALWAYS?

 

[Nige F]

I was right and yes there should always be water in the tank - about 4 inches in the bottom

 

[dilalio]

That tank should be full of water and should top up as needed via a ball valve. Check that tank has water in it and that ball valve allows fresh water in when float is pushed down.
The next issue to address is if you have blockages in the CH circuit due to that tank having been neglected and system water has sludge in it, hence poor circulation around ALL rads!

 

[dilalio]

And while you're at it... Check that magnaclean!

 

[Samsg30]

first of all, one thing has got very clear in my mind is that I have got open vented central heating system along with unvented indirect hot water megnaflo. So due to bit of confusion, there's one step missed yesterday whilst filling the CH system after draining. Sequence I followed was: -

1) Close bleeding valve in all radiators and leave the lockshield and TRV fully open.
2) Close drain valve on lowest radiator and remove hose (which I think is wrong as it should have left open for few minutes whilst system if filling???)
3) Open the mains cold water which started filling pipe and radiator
4) Bleed all radiators starting from ground floor and way up.

a) So, is my understanding correct that drain valve should be left open for some time so any air in the pipe is out?
b) if yes, do you think this could be a reason why some radiators are fully cold but upon bleeding them, only water is coming with no air?
c) How to resolve this issue without losing too much inhibitor as it costed me £50 to buy two bottles so don't want it to waste if can be saved.

Thanks