Heating not firing up boiler

[humantrafik]

Hello all,


This is my first post so please be gentle


Have a Potterton Suprima 50 bolier.



Gas central heating will not come on however, hot water fires up no problem. If I turn the room therostat up to 25 it does not fire up the boiler. We have two motorised valves which are two small white boxes(presumably one for heating one for hot water?) tried both of the valves in manual position, one of them made the usual whirring sound and so did the other, when putting back into auto poition. One of them now does not have any resistance when putting moving from manaul to auto and vice versa. Tried bumping the room thermostat again to 28 and resetting bolier but still not firing up for heating. All lights appear to be fine. The boiler has been on pretty much all the time.

Here is a photo which I hope helps. The bottom white motorised valve is the one which has lost it's resistance.




I was going to bleed the rads but would this be pointless if the valve might be faulty?


Thanks for any asistance that can be given.

 

[albatross]

I would say you need to get an engineer out to diagnose and repair it. If you post your location someone may be able to help.

 

[humantrafik]

Thanks for reply

Was kind of thinking that may be the case.

Located Huntingdon, Cambridgeshire

 

[Hanns21]

Sounds like you have a fault with one of your external controls ie room stat, moterised valve etc

 

[humantrafik]

Ok thanks for the advice already tested the room stat with multi-meter but all that proves is voltage is correct so may try another stat, other than that agree with motorised valve.

 

[Hanns21]

You can take the head of the moterised valve and by turning the room stat up and down you should be able to see the moterised valve open and closing. In the mean time if you switch the moterised valve into manual position using the lever at the side of it and switch on hot water on your time clock you will get heating and hot water at the same time

 

[stevetheplumber]

one motorised valve isnt working from what you say

 

[Hanns21]

Your problem now is testing if the room stat is sending a signal for the moterised t

 

[Hanns21]

Your problem now is testing if the room stat is sending a signal to the moterised valve. As it works like this... Time clock - room stat - moterised valve - boiler! But this means opening up the wiring centre and is dangerous if you dont know wat your doing?

 

[galaxy_plumbing]

you can try to gently tap it, its maybe just seized, but as said, it sounds like ch valve problem. get an engineer in

 

[humantrafik]

Thanks for suggestions so far.


Hanns21 will try your suggestion and let you know. One question tho if I have already verified the room stat and timer clock has power would it just be a case of tracing the motorised valve cable and testing with multi meter?


Galaxy, will give it a tap and let you know.


Thanks

 

[Hanns21]

Your room stat migth have power but is it switching and sending a switch live to the moterised valve? Sometimes the wiring centre has a picture inside which tells you the wiring diagram so its easy to tell. Its then just a matter of testing tht when you turn the room stat up you get a switch live to the moterised valve. Im 8/10 sure its a valve with your moterised valve faulty! You can buy the moterisef head by itself instead of buy the complete valve

 

[humantrafik]

Ok further diagnosis,


Replaced the stat still the same.


One thing I wanted to check for my own sanity there are two motorised valaves. The one in the pic you can see is a 2 port the other is hidden to the left of the pump hidden behind white pipes which is a 3 port valve. Am I right in thinking the 2 port is the one we suspect?



Took the two port valve head off which seems ok from visual inspection but questioning myself which one I'm supposed to be looking at?



Looked at the electrics and all tested fine on multi-meter. Also the 2 port does not stay in the manual position but also wondering should I be putting both valves into manual?


I will go and purchase a new head for the valve if we can decide this is the culprit.


Thanks again.

 

[albatross]

Need a hobby? Here's a fun way to fill your evenings:

Sit in the cold for a couple of weeks while poking a multimeter into things, not knowing which wires should give which results at which time or what conclusion to draw from your findings.

When you are bored of that game worry not, there is level two! Get a blindfold and a pin and open the screwfix catalogue on the heating controls page. Put on the blindfold. Stick the pin in the page and order that part. Fit the part and see if it makes a difference. Repeat this part of the game until you run out of money or get bored.

Congratulations! You are now ready for level three! Call a local heating engineer in to join the fun! You can tell him all the cool things you have tried and how much money you have spent having fun with your new guessing game! This man is magic you think! He must have played the game before! He guesses the right part in minutes! You are a little gutted about all the time and money you spent on the wrong bits but hey kid don't be hard on yourself it's only your first go and boy it was so much fun! Just the thrill of electrocution and house fires makes it so exciting and playing dens in a cold house is just like camping!

 

[humantrafik]

Albatross, I am amazed the time you took to reply to my thread....I’m flattered! Now I am thinking you have too much time on your hands because not much in the way of work because people find you abrasive and unhelpful? Therefore you named yourself after an endangered species (albatross) I do agree I need a professional to come in to confirm but at least I have had some degree of education. Who said my house is cold and I have spent lots of money? I would be seriously worried if you came to my house with that degree of logic.

Anyway off to call a pro (none with bird names or attitudes) then play level four where you have to destroy the big bad evil bird

 

[Hanns21]

The pipe going into the copper cyliner with moterised valve is for hot water, the other is heating! When you take the head of and turn up the room stat you should see the underneath of the valve move. It will also probably say on the brass fiting of moterised valve which position is open and which is closed. Its a easy of job to replace and not really expensive so i would just call someone that know what they doing and will have you up and running in a hour

 

[humantrafik]

Thanks again hans21 we need more people like you in the world.


I went a bought a new Danfoss valve at £40, isolated electrics, cut the old wire and carefully replaced wires one at a time noting position and colour, switched all back on and viola, we now have our heating back.


The job took me 20 mins.


As I have experience with electrics (did my C&G 2330 and the 2356) I would say call in the professionals if you are unfamiliar with this area.


Thanks again much appreciated happy days