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 unvented indirect cylinder 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 water pressure in heating.


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.

 

[REDSAW]

wrong pics, there be no loops around there

 

[samsg30]

This is all which is visible in air cupboard where cylinder is installed. Though this is unvented indirect cylinder from Heatrae Sadia megaflo eco but few pipes (including one cold supply) are going up in the loft area where there's a small tank with no valves as such. I guess this is bottle tank (as per glow worm flexicom hx guide).

Is this correct to assume that this tank will feed the water in cetnral heating automatically to pressure. Is the red pressure valve (show in other picture) controls the pressure automatically?

If yes, it is common for few radiators not to heat up automatically after system draining and re-filling but eventually getting hot if other radiators are turned off?

 

[Geyser]

Red valve is a bypass valve, nothing to do will filling pressure. Have you got a picture of the tank in loft?

 

[chris watkins]

Red valve is an automatic by-pass & should have been set to suit your system so don't touch it!

If there is a small (approx 0.6x0.4x0.5Metre high) tank in the loft with a pipe that connects to the heating system then this is what we call & F&E tank.

If most rads are working then those that aren't are almost certainly blocked with air.

 

[chris watkins]

I think you have a filling loop? it is a silver hose in your photo of the Megaflo behind the pipe that you call the "cold water inlet 3 bar") it seems to be coming from the cold mains & connecting to the primary "Flow".

Any plumber would have seen that ?

 

[Alex Knight]

Isn't the flexicom hx an open system boiler? The sx is the sealed system one?

 

[Riley]

I think you have a filling loop? it is a silver hose in your photo of the Megaflo behind the pipe that you call the "cold water inlet 3 bar") it seems to be coming from the cold mains & connecting to the primary "Flow".

Any plumber would have seen that ?

Christ you've got good eyes Chris. I am only looking on my phone though.
If you have a tank in the loft it won't be a sealed system. Where is the expAnsion vessel?

 

[Masood]

I think you have a filling loop? it is a silver hose in your photo of the Megaflo behind the pipe that you call the "cold water inlet 3 bar") it seems to be coming from the cold mains & connecting to the primary "Flow".

Any plumber would have seen that ?

That looked like 2 cables to me!

 

[Meady]

That looked like 2 cables to me!

Looks like 3 cables to me

 

[Stigster]

Looks like 3 cables to me

3rd'd! Them are cables.

 

[chris watkins]

That looked like 2 cables to me!

Looks like 3 cables to me

3rd'd! Them are cables.

Christ you've got good eyes Chris. I am only looking on my phone though.
If you have a tank in the loft it won't be a sealed system. Where is the expAnsion vessel?

OK, OK I take it all back :blush5: I can now see the stop valve below which must be on the mains coming down.

My only excuse is I was in a rush to get out this morning, it won't happen again, come to think of it it probably will cos i is old now.

Sorry Gents & OP'er

 

[JCplumb]

4thd'd !


Agree with your point above though, if some rads are working then it's a circulation issue.

 

[samsg30]

4thd'd !
View attachment 26061

Agree with your point above though, if some rads are working then it's a circulation issue.

I tried to bleed those cold radiators and water is coming out immediately. One of the cold radiator is actually towel rail in bathroom upstairs which is the highest radiator and I filled 2 liters of Fernox F1 inhibitor in it. Now when I bleed it, again water (or may be chemical) coming out immediately. Do you recommend I should let water come out for sometime to check if there's air stuck after it or should air always come out first irrespective if there's any?

 

[Howsie]

It sounds like you've got balancing issues or it's sludged up somewhere.

 

[samsg30]

Red valve is a bypass valve, nothing to do will filling pressure. Have you got a picture of the tank in loft?

Yes.. I managed to get in loft and there's a small blank tank covered with bit of black polythene but there are no valves at all what so ever. I haven't taken the pipe insulation off to check if someone has fit the compression valve instead which can be turned on/off using screw driver as I was expecting visible lever there. Other picture shows three pipes going up to the loft. One is mains cold water.

 

[kris]

Is there any pics of your boiler as nothing near your hot water cylinder, ?

 

[Howsie]

Yes.. I managed to get in loft and there's a small blank tank covered with bit of black polythene but there are no valves at all what so ever. I haven't taken the pipe insulation off to check if someone has fit the compression valve instead which can be turned on/off using screw driver as I was expecting visible lever there. Other picture shows three pipes going up to the loft. One is mains cold water.View attachment 26062View attachment 26063View attachment 26064

Is there water in that tank?

 

[kris]

The boiler you have is made as a heat only boiler, as its probably open vented, it can be fitted to an sealed system if appropriate safety features are added, the f22 fault is probably because you drained it and never bled the boiler or pump etc, have a look in the attic for a small plastic tank that will supply water to the boiler and rads, the f22 fault may also be a temp rise difference within boiler , ( circ problem due to air or lack of bleeding ), hope this helps mate

 

[samsg30]

Is there any pics of your boiler as nothing near your hot water cylinder, ?

attaching four pictures of boiler (Glow worm flexicom 30hx) which is suitable for both open vented and sealed system as per manufacturer's guide.

 

[samsg30]

The boiler you have is made as a heat only boiler, as its probably open vented, it can be fitted to an sealed system if appropriate safety features are added, the f22 fault is probably because you drained it and never bled the boiler or pump etc, have a look in the attic for a small plastic tank that will supply water to the boiler and rads, the f22 fault may also be a temp rise difference within boiler , ( circ problem due to air or lack of bleeding ), hope this helps mate

Looks like you are closing down on the issue... thanks mate. I only bleeded radiators.. don't know where to bleed boiler or pump from? There is definitely a plastic tank in the attic (as pictures posted above). Can you please suggest where to bleed boilder / pump from and is it as straight forward as bleeding radiators or I would be risking something big here.. like leak, permanent failure or massive issue?

 

[samsg30]

Is there water in that tank?

Haven't check the water as such. Should it be there or not?

I can get up to attic again and check.. it is a difficult place to get to and tank is closed with plastic strings..

 

[Howsie]

Haven't check the water as such. Should it be there or not?

I can get up to attic again and check.. it is a difficult place to get to and tank is closed with plastic strings..

Try bleeding the pump first, if no it's off to the attic you go.

 

[Geyser]

Looks like system is piped up in a way that will be hard to fill and be prone to air locks. No way to bled air from boiler return except on the compression joint. Feed and vent positions look wrong before pump but hard to see. I would repipe it or turn into a sealed system. I think you will keep getting problems as it is

 

[Alex Knight]

I'm going to say it's your pump.
You said you've got f.22 error on a glowworm that's not low water pressure (that's f9) f.22 I believe without checking is low flow rate through boiler/boiler flow return temp differential wrong
I would start with the pump.

Edit just checked, f22 is described as low water pressure but that doesnt really apply to this boiler with your setup

 

[Riley]

 

[samsg30]

Looks like system is piped up in a way that will be hard to fill and be prone to air locks. No way to bled air from boiler return except on the compression joint. Feed and vent positions look wrong before pump but hard to see. I would repipe it or turn into a sealed system. I think you will keep getting problems as it is

There's a drain valve on the bypass circuit (with red valve set on 0,4 bar). Is that where it should be and to be used to remove air lock? Else there are two radiators on ground floor where similar drain valve is present. I used one of them to drain the system and not other.

 

[samsg30]

I'm going to say it's your pump.
You said you've got f.22 error on a glowworm that's not low water pressure (that's f9) f.22 I believe without checking is low flow rate through boiler/boiler flow return temp differential wrong
I would start with the pump.

Edit just checked, f22 is described as low water pressure but that doesnt really apply to this boiler with your setup

Yep.. and that's the reason for this whole conversation that there was no filling loop to increase pressure. But now I know as this is open vented system, no need for pressure loop and pump is on the highest point already. F22 disappeared after resetting boiler twice, but many radiators were not getting hot.
Plumber advised to close TRV on radiators which are getting hot so water is pushed to other rads, which did a trick but still there are two rads (one on ground floor and other is towel rail where inhibitor was poured in) which are not getting hot at all and upon bleeding, cold water is coming out.

Not sure if there is air lock in the pipe as such which need to be vented out and how?

 

[Alex Knight]

What do you mean pump is on the highest point?
I've had plenty of pumps that run okay but are sludged up so they are not pushing water round as much as they should, only way of telling is by removing the pump head.

You can try shutting all the rads off apart from the two that don't work that should force any air out, I find flicking the pump between speeds quite often clears airlocks too, also check that the lockshield side of the radiator is open on the two that don't work