Motorized Vavle Failure

[PerpetualLeakingRoof]

Hi,

I went to test the heating system ready for the cold winter we've been promised this year and to my disappointment it wouldn't fire up

With the help of my sparky, who happened to be on site, we traced the problem to the PCB in the valve actuator. Manually opening the valve allowed the boiler to fire but clearly that isn't a long term solution.

The actuator that has failed is a two port Sunvic SZM 1801 (details: http://www.sunvic.co.uk/motorised_valves.htm). We have found someone local that can get us a replacement tomorrow but... this valve is only 2 years old and it's seen very little use. This guy http://www.seered.co.uk/sunvic.htm seems to feel that there is a basic design flaw in the actuator which will cause them to fail early. The fact that we phoned about a dozen plumbers merchants and didn't find a single one that stocked this part also makes me nervous - seems like the industry has made up it's mind.

So, would you just replace the actuator or replace the whole valve and if so what valve would you go for? We have to drain down the system to connect a radiator anyway so if we are going to replace the whole valve now would be the ideal time.

Many thanks

 

[kevplumb]

change it for a honeywell

 

[PerpetualLeakingRoof]

that's exactly what our sparky said.

I realize it's had to say for sure but do you think it will just be a case of removing the old valve and putting the new one in? In other words are the valve bodies likely to be about the same length? I'm asking so that I can judge roughly how long this job will take.

I know the Sunvic has 1/2" BSP threads and I'm guessing the Honeywell will as well. Is the Honeywell wired up the same way?