Automatic Bypass Valve Query

[John.g]

Both sides of the AAV got red hot??

OK' it looks as if it did, now can you set the AAV (temporarily) to index setting of 0.2 with boiler on, then stop the boiler and see if you are still getting that whooshing sound from the rad.

 

[Tigermad]

Both sides of the AAV got red hot??

OK' it looks as if it did, now can you set the AAV (temporarily) to index setting of 0.2 with boiler on, then stop the boiler and see if you are still getting that whooshing sound from the rad.

Thanks. Yes red hot. It only makes the crackling sound now and again. I can't make it do it so will have to test over a few days. Just for info when the boiler fired up the water loudly gushed around all the pipework for about 30 seconds or so.

 

[JTplumbingservices]

Hi. Sorry for the late replies I did not get notifications. The boiler is downstairs under the stairs directly below the airing cupboard. The pump is in the boiler I don't have one seperatesl as far as I know

From what I’m gathering from your info the flow is on the right hand of the pic and the zone valve is on the return. If this is the case then B has to go to the boiler for it to work the way it’s been piped.

 

[John.g]

Thanks. Yes red hot. It only makes the crackling sound now and again. I can't make it do it so will have to test over a few days. Just for info when the boiler fired up the water loudly gushed around all the pipework for about 30 seconds or so.

Gushing sound; sounds like air in the system.

 

[Tigermad]

From what I’m gathering from your info the flow is on the right hand of the pic and the zone valve is on the return. If this is the case then B has to go to the boiler for it to work the way it’s been piped.

Yes that's correct.

 

[Tigermad]

Gushing sound; sounds like air in the system.

There's nothing coming out of the rads when I bleed apart the from the towel rail that needs bleeding every week or so because the toprails don't get as warm. Lots of air comes out when I do that which is strange for a sealed system. Been doing it for over a year.

 

[JTplumbingservices]

There's nothing coming out of the rads when I bleed apart the from the towel rail that needs bleeding every week or so because the toprails don't get as warm. Lots of air comes out when I do that which is strange for a sealed system. Been doing it for over a year.

If the towel rail constantly needs bleeding and nothing else does then it could be an issue with the towel rail which is quite common

 

[John.g]

Is there a AAV (automatic air vent) or a number of them in your system, if there is just check if the little cap on the air nozzle(s) on top of the AAV is open or shut, some prefer just to open these occasionally just to check for any air once all the air has been expelled after a drain down/refill of the system.

What pump/model have you got and what setting is it on?.

 

[Tigermad]

Is there a AAV (automatic air vent) or a number of them in your system, if there is just check if the little cap on the air nozzle(s) on top of the AAV is open or shut, some prefer just to open these occasionally just to check for any air once all the air has been expelled after a drain down/refill of the system.

What pump/model have you got and what setting is it on?.

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?

 

[John.g]

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.

 

[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.