Reliable MOMO Valves?

[mickyg]

Lordy!
The proposition is that a motor on/motor off actuator will generally prove to be more reliable than a similar spring return actuator ( in which the motor is driven to one position and then remains stalled, with the power on, against the return spring).

yes theory is great, but in practice is what matters. As i said, sunvic momos are unreliable. Incidentally the older ones from the 80s seemed to last quite well, but all the ones obtained in the last 15yrs or so have been sh1te.
I don't care what "should" happen, only what does. I don't do my job based completely on theory, i leave that for the idiot specifiers who think things are as good as they are on paper.

It sounds like you've been binning them because you don't understand anything other than Y-plan and, maybe, S-plan.

I've been binning them because they're broken, duh! What you suppose I do with them? turn them into art? Whats that gotta do with what system they're attached to??? Why do you seem obsessed with challenging peoples levels of knowledge? Does it make you feel smart? do you think it makes you look clever? You know nothing about me, so don't assume. Maybe I should do the same? You didn't respond to my question about domestic repairs, so I will assume you don't do them. Maybe your a specifier, that would explain alot!!

 

[Onetap]

I've been binning them because they're broken, duh! What you suppose I do with them? turn them into art?

How about replacing the actuators with ones amended by the Seered bloke?

That would avoid draining down, removing valve(s), replacing valves, replacing controllers, refilling, etc.. Your customers would probably like that option. You probably have a few actuators lying around.

 

[Onetap]

You didn't respond to my question about domestic repairs, so I will assume you don't do them. Maybe your a specifier, that would explain alot!!

I don't think there was a question. What you said was;

Im beginning to think you've no experience of domestic repairs, in which case another pointless post.

That is not a question so I didn't give an answer.

I did domestic work, I moved on to other things.

 

[mickyg]

How about replacing the actuators with ones amended by the Seered bloke?

That would avoid draining down, removing valve(s), replacing valves, replacing controllers, refilling, etc.. Your customers would probably like that option. You probably have a few actuators lying around.

you can buy the head locally(no draining down), its called convenience. Customers don't want to hang around waiting for you to come back. 95% of customers want things done quickly and with little hassle/cost etc.
I'm seeing more bodies leaking/stiff etc now due to age of the valves and the systems they're on and complete valve changes can be quite common anyway.
I don't change enough these days for any other option to be worthwhile, they're becoming a very rare sight in domestic premises. I might see 1 a month if that, but I used to work in an area where there was alot wired in with relays.

 

[transam]

As far as I am concerned spring return M.V's are by far the better option poviding they are a decent make , which does not include Orkli , or the honeywell look alike made by Banico , infact anything with the Banico name on it might well be s**te (maybe ? allegedly ? possibly )

Rumour has it secret squirrels may be lurking , careful what one says ???

 

[SeeRed]

Copied from another thread, by way of explanation on this one!

As a scientist/engineer I mend quite a few of these as a hobby since first publishing my SeeRed webpages on Sunvic valves. The link is given above or just ask Google for SeeRed website + sunvic valves.

There are basically two types of domestic motorised valves - MoMo (motor on and motor off). These are in my view the best type if only because of the uniform motor torque available throughout the whole range of travel.

TWO PORT spring return use full motor voltage to stay in the open position and get warm, they eventually fail but often just because of an easily fixed microswitch problem. THREE PORT (mid position) use full motor voltage when fully open (central heat only) and reduced voltage (via diode and a resistor) when in mid position. These fail more often not because of motor failure but because at mid position full restore torque is not available and a sticky motor may not return reliably to the closed (dhw) position. Sunvic SD2701 and variants are notable here. They also have microswitch issues - again often easily fixed.

I am appalled by the number of actuators that are thrown away - when they can be mended for much less than the cost of a new actuator. This applies especially to the Sunvic MoMo design which is actually quite clever despite its design weakness, and is covered in my webpages. Sunvic 2301 and 2701 and variants are also thrown away in large numbers.

If any plumbers have a large box full of failed actuators I would be interested in obtaining these to see how many could be mended and to publicise this - as an aid to conservation and reducing waste.

Many householders pay over £100 to have an actuator replaced when often a £12 repair is all that is needed. Some installers replace programmers when it is just the motorised valve actuator that has an intermittent fault.