SUNVIC white box is making a noise

[Techboy]

This SUNVIC white box is making a noise - I don't know what it is

Please can you tell me what it is and if I can replace it myself or if I should get a plumber to replace it?

Video https://photos.app.goo.gl/5tsGCCKGkXKoTTu26

Thanks.

*edit SUNVIO/SUNVIC

 

[Harry Bloomfield]

You can replace the head part yourself. Is the red wheel moving? It will move very slowly.

It should move, if there is a change in demand from central heating to hot water or HW to CH. Once in position, it should stop its movement.

It's a Sunvic not Sunvio.

 

[Techboy]

I ran a hot tap for a few minutes and the red wheel didn't move.

I forgot to say that I have recently had issues with the hot water not getting hot, unless I also have the heating on - could this be the cause?

What do I need to buy as a replacement?

 

[Harry Bloomfield]

Running the hot tap will not necessarily cause it to move. The only thing which will cause the red wheel to change position is a change in demand for heat from the cylinder, when there has been no demand before it. It allows hot water from the boiler, to be diverted through the cylinder. That assumes HW is enabled by the clock or timer.

Idea is it open the valve it controls, or closes it. It will only move when a change in position is needed - when not needed to move, it should be silent. Is it constantly making a noise? If it is, it suggests the position should be changing, but isn't.

 

[Techboy]

Thank you, very helpful

From reading/watching

and http://www.seered.co.uk/sunvic.htm, plus the noise it's making, I think it's a mechanical issue, not an electrical issue, so I'll get a replacement and fit it myself as you suggested.

I could get a replacement Sunvic Actuator SZM 1801 but I'll get the Sunvic 2 Port EcoSmart Valve version, as the website says it should pay for itself during its lifetime. I haven't been able to find any online yet, so I might need to e-mail Sunvic to ask where I can buy one!

 

[Techboy]

Or can I replace it with another make instead? Honeywell seem to get good reviews and are available in more shops. I'm not sure which one I need though... https://heatingcontrols.honeywellhome.com/products/Valves/Motorised-Valves/V4043-Motorised-Valves/

Also, I like that with the Honeywell, you can replace just the motor, you don't have to replace the whole unit.

 

[oilhead]

If you just want to change the actuator, then you need to go like for like. Changing to Honeywell will need a drain down as you need to change the valve. The Eco smart unit may use the same valve body, but will need significant wiring changes.
If you think it is just the motor failed, then change just that in the Sunvic unit. It is a standard Synchron unit, but use a genuine Synchron rather than a cheap look a like.

 

[Harry Bloomfield]

Only like for like actuators will work with the valve, they are a pair. The only way to swap make/models, is to swap actuator and the valve as a pair.

Looking at your photos, I see some evidence of what might be rust at the base of the actuator. Might it have suffered from water? Those actuator models are very reliable, but water can kill them quite easily. If the valve is leaking, that would explain it, so worth swapping as a pair.

Plenty of Sunvic SZM 1801 heads on ebay...
https://www.ebay.co.uk/sch/i.html?_from=R40&_trksid=m570.l1313&_nkw=szm+1801&_sacat=0

 

[Techboy]

Thanks, I'll swap for another Sunvic Actuator SZM 1801 if I need to.

Yes, I think it is probably just the motor that has failed and I'm happy to have a go at replacing it myself. Any recommendations for which one? I'm not sure if this one is official and fits... It has a lot of good reviews https://www.amazon.co.uk/Replacemen...ild=1&keywords=Synchron&qid=1589720967&sr=8-3

 

[ianmcd]

Is that an unvented Hot water cylinder that you have ?

 

[Techboy]

Sorry, I don't know. I know very little about plumbing Here are some photos:

 

[Harry Bloomfield]

Its an unvented!

 

[Techboy]

Would you recommend one of these?:

DRAYTON SYNCHRONOUS MOTOR (28670) https://www.screwfix.com/p/drayton-...JiwZ37DhIq9Kf_uXfiRoCC5sQAvD_BwE&gclsrc=aw.ds

Replacement Synchronous Motor for motorised valves ACL Honeywell Landis Gye Satchwell Sopec Tower DIY Replacement 2-port 3-port valve failure https://www.amazon.co.uk/Replacemen...ild=1&keywords=Synchron&qid=1589720967&sr=8-3

 

[Techboy]

Or should I replace the whole thing...? https://www.dhsspares.co.uk/product...LgrI4j-rLyQhBguA0UTtkAry5gdPGCMRoCQ_QQAvD_BwE

 

[Harry Bloomfield]

Replace the whole head - I think the motor is different to the usual one anyway, so a new motor might not help.

But before doing that, you need to know why the original one failed. Is that rust on the baseplate, what has caused it, is the valve spindle leaking?

If leaking you need to replace both head and valve, or the new head will fail.