'Normal' solenoid valve coil resistance?

[rebuke]

I've just installed a new Triton 9.5kW electric shower. Unfortunately, it doesn't seem to work properly, in that very little water comes out (a small trickle, and as you turn the flow control up, it just kicks in the low pressure neon). I've checked the pipework to it, and that seems clear, good pressure comes out of it (I flushed it all through before connecting it to the shower etc). I've checked the filter in the shower, and that's fine, and it's definitely on the mains and not tank fed (verified by turning the stop cock off).

I've spoken to Triton on the phone, and they suspect it's the solenoid valve, and are sending someone out next Wednesday - if however it's something I've done wrong, then I'll have to pay the call out charge, so I'd like to verify it's the solenoid as far as possible. I've measured the resistance of it, and I get 3.63 Kohms. I've seen a figure of 3.5 stated as 'normal' before, but is that ohms or kohms (from my understanding of electromagnets etc, I suspect ohms, which would seem to imply the valve is faulty, but I'm not sure)?

Also, does anybody know what's involved in changing the solenoid if it is faulty - will the engineer have to take it off the wall (would be tedious if so as will have to re-do all the silicone round it etc...)?

 

[swbjackson]

Have a look at the installation manual. Most electric showers are not meant to be siliconed round. They generally stand slightly proud of the wall to allow for better cooling. You may want to remove the sealant before the service engineer arrives.

Mike

 

[TicklyT]

I would expect the solenoid resistance to be in the Kilohm range, otherwise the solenoid would use more power than the shower heater!

230 Volts / 3500 Ohms = 66 Miliamps, or about 15 Watts - that sounds about the right order of magnitude.

If it was 3.5 Ohms, the solenoid would draw 230 Volts / 3.5 Ohms = 66 Amps, or 15 Kilowatts

In general, the magnetic power of a solenoid is proportional to the number of turns of wire multiplied by the current flowing through the wire, so they tend to have as many turns as possible wound on the coil former to keep the current consumption as low as possible.

 

[rebuke]

The manual doesn't say anything about it either way, and it doesn't sit proud, it goes flush against the wall (it's a Triton T80xr if anybody is familiar with it), which is why I (or at least my mate who was giving me a hand with it) sealed it.

TicklyT that's a very good point, I guess it could still be the solenoid having a mechanical fault (can't open all the way or whatever), I guess the only other thing likely is a blockage somewhere in the shower itself (since I know that there is good pressure from the pipework). Looks like I'll just have to see what the Triton person says when he turns up, and if I have screwed something up, then pay the call out fee - oh the joys of plumbing...

(Before anybody asks, I have notified my LABC with regards to the electrical side of this, as although I've replaced a previous shower, I've run a new cable because the original one wasn't the correct size etc etc...)

 

[lordwoody]

I am fitting a 2nd hand Triton Opal 2 shower that was removed serviceable because of a power shower upgrade and I thought I would test the Solenoid Resistance which Triton say should read 3.5 Kilohm,

The one I have read 3.486 would the tolerance of 0.014 make any difference?

 

[seco services]

The one I have read 3.486 would the tolerance of 0.014 make any difference?

no

 

[Agile]

(Before anybody asks, I have notified my LABC with regards to the electrical side of this, as although I've replaced a previous shower, I've run a new cable because the original one wasn't the correct size etc etc...)

Quite apart from needing to be fed from an RCD circuit and having an isolator outside the bathroom, I have always thought that the actual work has to be done by a qualified electrician. Although perhaps you are but in that case you would know all about solenoids!

Its quite possible that the solenoid is not opening fully. However I would have expected that even Triton ( about the worst manufacturer ) would have tested the shower with real water and noticed the lack of flow?

Have you measured the flow rate with the shower not connected?

Tony

 

[FiremanT]

Just as a matter of interest (nosiness), how much is the call out if you have to pay it?

 

[Agile]

Probably MORE than the cost of a bottom of the market Triton shower!

 

[Richardthe3rd]

I thought in England any electrical work in a 'wet room' like kitchen or bathroom you needed a Part P?? I think here you need 17th Edition.

 

[stardanny]

Yes, for a full wetroom shower.

Also the topic is 5 years old

Daniel.