Why do my 2 port motorised valves not last?

[tommybanana]

1st valve lasted 7 or 8 years. Second one 2 years. Now another one on a different zone is opening but not sending a live switch signal out. Worked around it by sending the thermostat -on live signal to the boiler so dont need valve microswitchbto work. Any advice on getting valves to last longer.
Best tommy banana

 

[swbjackson]

What make are they? Different valves are built to a different standard.

 

[tommybanana]

Honeywell
Best
T

 

[ALEC1]

design them out is the best option in my opinion... the ones sold in the UK are a model developed over 50 years ago. In the rest of europe they sell more robust ones working a lower voltages although some are 240vs...

 

[tommybanana]

what would you guys recommend as an alternate - either a 2 port valve or a design alternative?

best

tommy b.

 

[swbjackson]

I'm using Sauter ones at the moment, detachable head, plug in wiring and a 5 year warranty.

 

[dcawkwell]

Are you replacing the head? Always replace the whole valve not just the head.

 

[Boilerman2]

Why would you change the WHOLE VALVE???!

230v present but valve not opening - new Sychron motor (cheap repair)
Motor opens, but no signal to boiler/pump, New head, but sometimes just microswitch
Valve letting by, fit a service pack (Ball & o ring kit) (cheap repair)

It must be VERY unusual to have to replace the WHOLE valve!