Automatic Bypass Valve Query

[Tigermad]

I had an automatic bypass valve fitted to my unvented system yesterday and it was left at 0.4. Goes from 0.1-0.5. Anyhow I thought I would set it today according to the instructions. So I closed it off completely to th 0.5 mark and then turned all the trvs on. I then began turning it until the pipe started to get warm. Problem is the abv is in the airing cupboard and it is fitted to the pipes marked flow and return. The flow pipe is hot but the return pipe remains stone cold. Even after leaving the heating on for 10 minutes. So turning the valve makes no difference. Am I doing something wrong? Why is the return pipe stone cold?
I just tried turning the heating off and the pipe from the ABV got red hot even though the ABV is turned off

Ignore the non copper pipes. These are from the old system and are redundant.

 

[Tigermad]

That's correct (gas boiler) and you can't access it (not GSR) , post #57 above suggests that it could be a issue with the towel rail.

I meant to ask you this before, why did you decide to fit a ABV??, was it because the boiler manufacturers require it or some other reason.

Yes the boiler recommend it even when there is one built in. This is if all there wasn't a bypass rad. Also since the unvented system was fitted the radiators make a loud hissing noise so the installer recommended he try this to see if it helps. Since the bypass was fitted and inhibitor put in it is now have hissing and crackling. Wish I didn't bother to upgrade now. Cost me over £6k

 

[John.g]

You would think the installer should sort it out if these problems are there from the time of the upgrade but you probably know all this, I'm afraid I can't offer you any other suggestions.

 

[John.g]

Hi. No aavs on system. The only pump I have is inside the boiler as far as I know. Is that right for an unvented system?

The boiler probably has one, there should certainly be at least one more installed in the system, this is often on a T piece where the cylinder coil enters the cylinder top and before any MV.

 

[Tigermad]

Will have to see if I can see one on any of the pipework. Never told about it anyway.

 

[John.g]

I have a feeling that the ABV when opening is allowing trapped air in your system into the return and causing all sorts of issues (not the ABVs fault) , if a AAV or manual air release isn't fitted then how was the air in the system initially released on refilling the system I wonder, the boiler AAV is fitted to remove air from the boiler and not the system but may do so over a prolonged period but I wouldn't bet on it.
One other query, if there is a pressure gauge in the boiler display, it should read ~ 1bar when cold and ~ 1.5 to 2.0 bar hot.

 

[Tigermad]

I have a feeling that the ABV when opening is allowing trapped air in your system into the return and causing all sorts of issues (not the ABVs fault) , if a AAV or manual air release isn't fitted then how was the air in the system initially released on refilling the system I wonder, the boiler AAV is fitted to remove air from the boiler and not the system but may do so over a prolonged period but I wouldn't bet on it.
One other query, if there is a pressure gauge in the boiler display, it should read ~ 1bar when cold and ~ 1.5 to 2.o bar hot.

Had a look and can’t see one on any pipework. Yes pressure is fine under 2 when hot and a tiny bit over 1 when cold.

I think the air got in when refilling and wasn’t released.

 

[John.g]

Would advise then to get your installer or plumber to install one ASAP.

 

[Tigermad]

Would advise then to get your installer or plumber to install one ASAP.

He’s been installing for over 30 years. Surely he would have put one there?

 

[Tigermad]

He’s been installing for over 30 years. Surely he would have put one there?

Would advise then to get your installer or plumber to install one ASAP.

Replied above about the pressure question.

 

[John.g]

He’s been installing for over 30 years. Surely he would have put one there?

He’s been installing for over 30 years. Surely he would have put one there?

Can't answer that one, is he aware that you are still having problems after the fitting of the ABV?, if not just pick up the phone and ask him to return and sort things out, your system never seems to have been right since the upgrade.

 

[Tigermad]

Can't answer that one, is he aware that you are still having problems after the fitting of the ABV?, if not just pick up the phone and ask him to return and sort things out, your system never seems to have been right since the upgrade.

He has ignored me unfortunately.

 

[John.g]

OK then, there must be plenty of good plumbers in your area, I'm sure there is some way on here that you can privately (conversation?) ask one of the many professionals on here if they could recommend one near you.

 

[Tigermad]

Bit of news. Plumber who installed the system contacted me tonight after I texted again. He said he is happy to come out to take a look if I want him to.

 

[John.g]

Great news, let us know the final outcome please.