three way valve sticks between hot water and central heating.

[plumbam]

Hello all,

My 3 way valve sometimes sticks between c/h and h/w resulting in rads warming up when timer is
turning h/w on.
The valve is sunvic 2701 it moves the full range for c/h or h/w on the motorised bit.
the valve body was a bit stiff but still moveable with the fingers.
I have bought a new valve body (danfoss randall hsv3) and hope to change it to see if this brings an improvement.

Will I get away with isolating cold mains and cold feed to h/w tank then draining taps rather than all the
radiators when attempting this?

Do I need to turn valves off above and below the pump?

can I use that slotted thumbwheel on vertical pipe ajoining hot feed to h/w tank to bleed h/w side when I am done?

Does the pump - pump water to the T junction 3 way valve or draw water through it?

Thanks for reading and any advice.

Cheers,
Tom.

 

[Billy Bob Bob]

You need a plumber,no disrespect intended but obvious by your post you dont have a clue where to start

 

[SimonG]

You are getting confused between the different types of pipework. Maybe best to call in a professional. Your house insurance won't cover any diy misshaps.

 

[plumbam]

Hi,

Thanks for the advice.
Regarding my vented system
If I go ahead and get the three way valve (diverter valve) changed should I get the wsp gold
pump changed at the same time (if so what type would you recommend)? The system is 24 years old and original.
All the radiators still get hot.

 

[ShaunCorbs]

Yes best to replace the pump I would recommend dab pumps

 

[tamz]

I wouldn't bother with the pump. If it ever does need changed its a 10 minute job.

 

[plumbam]

I sorted it in the end replaced 3 way valve and motorised bit. isolated tank in the loft. drained radiators. cleaned with flushing agent.
drained topped up with inhibitor bled radiators.
I left the pump for now. bled the feed into the hw tank and primed the pump to get it started again.all working and switching ok.

 

[plumbam]

I sorted it in the end replaced 3 way valve and motorised bit. isolated tank in the loft. drained radiators. cleaned with flushing agent.
drained topped up with inhibitor bled radiators.
I left the pump for now. bled the feed into the hw tank and primed the pump to get it started again.all working and switching ok.