HW only when CH is on

[LozzaC]

Hi all,

I have a problem whereby my hot water only seems to get truly hot when the CH is on (and takes longer than it should). Following the boiler troubleshooting guide & looking through the forums it seems like this may be an issue with the 3-way valve. I have a Potterton Profile boiler. The 3-way valve is a Honeywell V4073A1088 (i.e. the 28mm version). When HW only is selected on the programmer, the inlet pipework to the cylinder gets hot, but the outlet does not get very warm (suggests flow is restricted in the feed to the cylinder by the 3-way valve?). From what I read, the problem could be that the valve is stuck.
What is the best (& easiest!) way to check what needs to be replaced - it's not cost driven really, just would rather not have to drain down to change the whole valve i.e. just change the motor/actuator?

Thanks in anticipation

Lozza

 

[seco services]

with hw on only. check the lever on the end of the valve, push it across is it loose or has it resistance on it ?

have you a gate valve fitted on the return pipe from the cylinder ?

 

[LozzaC]

with hw on only. check the lever on the end of the valve, push it across is it loose or has it resistance on it ?

have you a gate valve fitted on the return pipe from the cylinder ?

Hi, no resistence when pushing the lever back and forth.
No gate valve fitted on the return to the boiler.

Thanks!

 

[seco services]

do your rads get hot when only hw on ?

 

[LozzaC]

do your rads get hot when only hw on ?

Yes they do.

 

[seco services]

sounds like the valve spindle sticking

 

[LozzaC]

sounds like the valve spindle sticking

OK, thanks. What's the best approach - take it apart & give it a clean? Can that be done without draining down?

Cheers

Lozza

 

[twgas]

Drain and replace, a clean may help but only for a short while.
Add inhibitor when done - may even need a clean before you change the valve.

 

[LozzaC]

Drain and replace, a clean may help but only for a short while.
Add inhibitor when done - may even need a clean before you change the valve.

Was afraid of that... Thanks guys. One for the weekend. At least it's getting warmer now

Lozza