Lockshield valve for Cylinder?

[gungaabayar]

Hi All

I got open vent system with 2 zone valve. I am not able to put CH and DHW on same time cos there is no lockshield valve on Cylinder's flow and return. Everytime put both of them on DHW pipe steals all heating.

After DHW zone valve 22mm pipe goes to cylinder and returns to main return pipe. Can I just put 22mm Lockshield ball valve in the middle of the pipe which goes to cylinder and balance all system so that heating spread evenly or have to put lockshield valve just before or after Cylinder like radiators lockshield valve?

There is not much space to put lockshield valve just around the cylinder because of tight airing board.

any help will be much appreciated,

cheers

 

[stevetheplumber]

providing its on the flow or return to the cylinder only ie after the pipes split to heating

 

[Best]

it is a gatevalve you need, lockshield preferably, but an ordinary gatevalve would do.

 

[jtsplumbing]

Could be that cylinder return is connected in wrong place, needs to be last connection B4 boiler

 

[gungaabayar]

so you are sayng anywhere in the yellow highlighted pipe on the attached diagram which is my flat layout (ish)?

 

[jtsplumbing]

Had this problem B4 you may have to put a check valve on return pipe just after the tee B4 the boiler, or re-run the return from the cylinder as close as poss to boiler

 

[stevetheplumber]

that layout looks fine valve goes any where between the return tapping on cylinder and first tee or if necessary after the motorised valve on the flow

 

[chris watkins]

Hi All

I got open vent system with 2 zone valve. I am not able to put CH and DHW on same time cos there is no lockshield valve on Cylinder's flow and return. Everytime put both of them on DHW pipe steals all heating.
cheers

Can I ask why it is that you want to have both on at the same time ?

Why not have the hot water on first for say 30 - 40 mins then bring the heating on, the cylinder should be hot by then so all boiler power will then go to heating.

This is the modern energy efficient way with condensing boilers.

 

[gungaabayar]

Can I ask why it is that you want to have both on at the same time ?

Why not have the hot water on first for say 30 - 40 mins then bring the heating on, the cylinder should be hot by then so all boiler power will then go to heating.

This is the modern energy efficient way with condensing boilers.

This morning, I tried exactly what you said , unfortunately as there is no lockshield valve (balancing ) for the cylinder most of the hot water still travel to cylinder and back to the boiler through the last tee in which DHW and Heating returns meet. Also rads are not warm enough so after the meeting tee cold ish water goes to boiler return and boiler works in high demand and uses a lot gas.

before I never put both DHW and Heating on same time anyway. But this morning I was thinking like I might get hot water in cylinder without extra gas bill putting DHW on while heating is on.

I still think I do need lockshield valve for cylinder to get system properly balanced right?

many thanks

 

[chris watkins]

You don't need one, there is something else wrong.

 

[gungaabayar]

You don't need one, there is something else wrong.

might be, but what could it be?

its is an old system, apparently been in this flat last 30ish years. As far as I know new boiler (Ideal Logic heat 15) , a pump (grundfos Alpha2L) and all rads changed. powerflushed, and cleaned using X400.

heating or hot water works fine if they work separately. Pump speed put on 2, not 3. If put pump at speed 3 it might be better than 2 but dont want pump work at highest speed.


So what could be wrong?

cheers

 

[chris watkins]

By-pass or pump most likely

Is the by-pass manual i.e gate valve or Auto spring loaded valve which adjusts with the system pressure ?

Do you know about the Alpha 2L's what setting is it on (not just speed) has it been commissioned correctly?

 

[gungaabayar]

By-pass or pump most likely

Is the by-pass manual i.e gate valve or Auto spring loaded valve which adjusts with the system pressure ?

Do you know about the Alpha 2L's what setting is it on (not just speed) has it been commissioned correctly?

Hi again, I put new auto bypass valve month ago . Old one was gate valve.
a plumber installed the pump year ago, the setting was CP2 but it was not worked properly so I put constant speed 2 then seems work fine, is it the settings you are talking about.

no idea what is commissionig the pump tbh, how to commission the pump anyway?

The actual pump is Alpha2L 15-50 130.

cheers

 

[Rckape]

Did you follow the instructions on correctly adjusting the auto bypass valve? They need adjusting to your pump.

 

[gungaabayar]

Did you follow the instructions on correctly adjusting the auto bypass valve? They need adjusting to your pump.

I put ABV to 0.1 bar. I never noticed water goes through the valve ever. When boiler turns off I was expecting water goes through the valve cos zone valves are closed, pump still on and boiler stops burning but seems like its internal fan is working. It makes me think if pump overrun is active after boiler off,

as I put AutoBV I cant choose PP1 or PP2, so have to choose either fixed speed or CP1 or CP2 mode on the pump. CP modes seems not working correctly, so chosen fixed speed 2

P.S. there is only one TRV in the system which is always open.

 

[oz-plumber]

You're correct with one thing.
The pump will run on for a period of time after the boiler has shut down.

As for not by-passing through your BPV, there is obviously something that hasn't been done correctly.

Have you installed it the correct way?