hot water is on all the time

[Mike19]

Hi all, can some one give me some advice please, i have just fitted a new three way valve to my system and rewired some parts. it all works ok but the hot water comes on even when the programmer is turned off. i used a wiring diagram that came with the programmer and cross refereced it with others that i downloded off the internet.
i would be most greatfull for any help. thanks Mike 19

Myson Appollo Fanfare Boiler, Boss BMPV28 valve, Lifestyle LP522 Programmer

 

[Softus]

Hi all, can some one give me some advice please, i have just fitted a new three way valve to my system...

What was the old valve Mike? Or are you adding one where there was none before?

...and rewired some parts.

Could you provide a bit more detail of what you did?

it all works ok but the hot water comes on even when the programmer is turned off.

Do you have a cylinder thermostat? If so, check the path of the feed to that stat and to the MZV.

 

[Mike19]

Thanks for the quick responce Softus. The old valve was Honywell V4073A1062-7
it had BSP ports that had BSP to 28 mm converters in and an adapter plate on the valve head. I changed the valve to bring the system up to standard and the valve head wanted changing.The system has not been running right for some time. hot water and heating came on togeather.
I have checked the wiring path and it seems to be wired correctly
I rewired the programmer and the cyl stat.
I have an idea that i could be the over run themostat thats faulty.
Thanks Mike19.