Faulty Immersion & 3-Port Valve? How To Test?

[brummydave]

Called today to a mixture of faults, main concern being 'no hot water!'

Firstly, the immersion was blowing the rewirable fuse. Discovered the thermostat had been left at 80degC and they've been using it a lot lately rather than the gas boiler. Methinks something has overheated and given up? I did trace the probable culprit to a line-earth short. The neutral to line resistance was varying, but around 120 Ohms. I think this points to a faulty immersion heater rather than thermostat?

FYI It's a top fitted one but as it doesn't look like it's been pulled for a while my advice was get a plumber to change it incase all goes wetpear-shaped!

Second, the y-plan system was being a bit weird - The mid position valve has me confused. When water was set on, and the cylinder stat turned up, the boiler fired, pipes got hot. result. when cyl stat turned down, boiler went off. When heating only set on, boiler fired, pipes get hot. When both on, still ok. However, later discovered when water only on, the radiators were getting hot! Not nice in this weather . The little manual lever seemed to only be moved from centre to the 'manual' end and never all the way to the 'auto' end.

What fault does this point to please? Valve, motor or actuator?

FYI the cylinder stat was originally set at 50deg, there's no room stat and a 'classic' honeywell programmer which annoyingly loses programs every time power is off.

Thanks for your time,

Dave.

 

[steptoe]

get a proper spark in that knows how to wire heating systems,

sorry,

but Im totally fed up with going sorting heating systems after someone that knew what they were doing done it, but its never worked right ,

:shakehead

sorry if that sounds bad, but its doing my head in, they pay some monkey a stupid amount of money to wire it wrong, then they expect me to fix it for £30

F that,

ive worked a long time to get my knowledge, Im finished trying to tell people how to do stuff they should already know if they claim to be a spark.!#

 

[ProDave]

3 port valve explained http://www.gasheating.co.uk/Mid-Position-Valve.html

Personally I would never fit one, they are the work of the devil. I would use two 2 port valves instead.

 

[brummydave]

get a proper spark in that knows how to wire heating systems,

sorry,

but Im totally fed up with going sorting heating systems after someone that knew what they were doing done it, but its never worked right ,

:shakehead

sorry if that sounds bad, but its doing my head in, they pay some monkey a stupid amount of money to wire it wrong, then they expect me to fix it for £30

F that,

ive worked a long time to get my knowledge, Im finished trying to tell people how to do stuff they should already know if they claim to be a spark.!#

Sorry about formatting of OP, my Firefox is playing up. Made it more legible in Chrome now.

Not sure why you bothered replying with that info steps, i was after useful tips and help not a rant. I do know how to wire a heating system up, I have done several and am always trying to improve customers controls to make them more user friendly and efficient. 

I'm not however a plumber or particularly experienced with fault finding on central heating systems, hence my request for advice. The wiring is all in good order, it's the parts on the end of it that are not operating correctly. 

If anybody has experience with Honeywell 3 way mid-position valves and is willing to share it, i'd be most grateful.

TTFN

Dave.

3 port valve explained http://www.gasheating.co.uk/Mid-Position-Valve.html

Personally I would never fit one, they are the work of the devil. I would use two 2 port valves instead.

Thanks Dave, so I need to return and check voltages on the wires then. 

Any idea on the slider position for the Honeywell actuator?

 

[steptoe]

Sorry about formatting of OP, my Firefox is playing up. Made it more legible in Chrome now.

Not sure why you bothered replying with that info steps, i was after useful tips and help not a rant. I do know how to wire a heating system up, I have done several and am always trying to improve customers controls to make them more user friendly and efficient. 

I'm not however a plumber or particularly experienced with fault finding on central heating systems, hence my request for advice. The wiring is all in good order, it's the parts on the end of it that are not operating correctly. 

If anybody has experience with Honeywell 3 way mid-position valves and is willing to share it, i'd be most grateful.

TTFN

Dave.

Thanks Dave, so I need to return and check voltages on the wires then. 

Any idea on the slider position for the Honeywell actuator?

obviously not,

there is a big difference between knowing how to connect them and knowing how to wire them,

if you knew how to wire them this is a fairly simple question.

and, its not a rant, just a statement of fact.

I get this regularly, maybe 2 a week, so its a fact that people that think they know how to connect them, dont know how to wire them.

 

[SPECIAL LOCATION]

There are loads of threads on 3 port valves....

if you do a search of the forum I am sure you will find some...

I know for a fact that ProDave, Steptoe, KME, Myself and others.. have described the inner workings and wiring and fault finding numerous times before.... 

I am too busy to start typing it all out again..

But as has been pointed out anyone who genuinely understands how and why they are wired in a certain way.

will have no trouble fault finding back in the opposite way!!

Guinness

re, Immersion heater, did you disconnect the cable from the element to prove the cable itself was still all electrically sound?? 

:C

 

[brummydave]

Thanks.

Yes I tested the cable itself and it was fine.

And i tried several searches on the forum but didn't get much. Will try again in daylight on bigger screen to see if more can be done. Thanks for the tips, nighty night.

 

[SPECIAL LOCATION]

Try the Advanced Search option..

with something like "3 port valve" in the search text..



:Salute

 

[kme]

I found ALL the previous threads on this, in a min or two - quicker than waiting for someone to see the new post, and reply to it, to be honest.

Don`t get us wrong - none of us are being "unhelpful" - though you may think otherwise. As SpecLoc says, we`ve done this exact same thing, many times on here - and, as helpful as we like to be, being able to carry out basic diagnostics is part & parcel of our trade.

But, we have, in the past, explained in really simple steps, how they work & how to test / fault find them. I haven`t been posting much recently, `cos its 10.30 or later when I finish my office work; I`m out at 6 or 7 in the morning, and I`ve not had the time I`d like to spend here - time I`m certainly not going to spend re-hashing a subject we`ve already covered, and is easily accessible to all - sorry

 

[brummydave]

Thanks kme. Maybe the simple step by step posts could be made into guides and then made a sticky to ease finding?

I realised my problem in finding posts was an inability to select the correct search function coupled with a malfunctioning Flash plugin. Too many old versions lurking around so after uninstalling flash, restarting my system then reinstalling flash I have a better functioning Firefox. (TEF still needs to be used in Chrome tho )

However I do like a challenge and after spending three hours today trawling the TEF and the internet I have conclusively found lots of info on how 3 port valves work and how to test the wiring, spindles etc etc.I presumed that because the heating had worked previously I wouldn't need to check the wiring connections but it would appear prudent to do so on a repeat visit.

I haven't found any reference on here to where the little slide lever should be positioned but on Honeywell's site they mention in the V4073A FAQ that the lever has no relation to the position of the valve!  http://www.honeywelluk.com/professional-zone/resource-centre/Wiring-Diagrams/.

I have also found http://www.lovekin.n...lve-faults.html which is very detailed and will help with the fault finding

With regards to the immersion heater, I've found information on typical resistances for healthy elements and mine's way over. I'll stick with recommending a plumber changes it for a new one. Posts on here concur - old tanks may crease and split, tank needs draining a bit, elements have most likely broken and the 3036 fuse won't pick that up etc etc.

 
I fully appreciate the time it takes to type helpful responses - many of us are very grateful for the forum's years of wisdom. I do normally search thoroughly before posting a similar thread to what has been before. Genuinely in this case it seemed more time efficient to put my own questions up. 

 
Anyhoo, sun is shining and wires need attending to.
Thanks for all your time and helpful pointers, time to go to work.
TTFN
D.

 

[ProDave]

The override levers vary from manufacturer to manufacturer. but they certainly DO move the physical valve, but not always the motor, if that makes sense. but usually on a 3 port valve there's only an option to override it one way, and no choice to manually lock it in the three possible positions.

another reason I would personally not plumb a system with a 3 port valve.

Don't forget, many motorised valve problems are nothing to do with the motor or wiring, the valves themselves can stick. Take the actuator off, and make sure the spindle of the valve rotates freely without sticking at any point. If it does stick in places, the valve body will need to be replaced, and that's a job for a plumber. 

 

[Doc Hudson]

.I presumed that because the heating had worked previously I wouldn't need to check the wiring connections but it would appear prudent to do so on a repeat visit.

The basic rule for any wiring fault finding, (not just heating controls), is never assume anything that you haven't proved yourself. Irrespective of what a customer may or may not say about what or when something has or hasn't happened. If you don't test and verify all relevant cables, connections, voltages, polarities etc.. you are at some stage guaranteed to get led up a wrong line of investigation because something you thought was correct was never correct. Some jobs have been wired wrong since day1, others may have been messed with by a plumber or DIY, before they call you in to investigate. All heating is simply a supply controlling a load, via various combinations of Manual switches, Timer switches, Thermostat switches, Valve position switches. Take a step by step approach checking the circuit through from supply to load.

A problem that Steptoe hinted at is that some people can only copy wire positions from various manufactures wiring center diagrams without having a clue as to the actual purpose or function of any of the wires. Providing you understand what the various wires are actually doing, then central heating control is not much harder than two or three way light switching. A few parallel and series switching paths to fire a boiler, with some taking a priority over others.

Also as a general rule the levers are there to provide manual positioning of a valve, they are not there to give an indication of the electrical position of a valve. So in many cases just looking at the lever will not tell you much.

Doc H.

 

[brummydave]

Thanks Doc & Dave. Much appreciated

 

[binky]

Not sure why you bothered replying with that info steps, i was after useful tips and help not a rant.

This is Steps being helpful, just not good at being diplomatic  :^O    he says it as he sees it, could do with more politicians like that ......whatever happened to 'conviction politicians' with real causes to persue???