Changing old room thermostat to new programmable one HELP!

[EvertonHero]

Hi all long time reader first time poster go easy on me

Right i have uploaded some photos to my album to make it abit easier to talk about,

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• EvertonHero
• 7 Feb 2012
• 1

My old theremostat was just a dial to set the temp,1st problem/situation is no matter what was set on the clock under the boiler for CH off/timed/on etc it would not effect any of the house temp unless this dial has moved.

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• EvertonHero
• 7 Feb 2012
• 1

so even if i set the boiler to kick in at 5am it wont go above whatever was preset on the dial, but anytime of the day i can turn the dial up and it will kick in which is becoming a pain waking up & coming home to a coldhouse every day

So i thought id buy a prog thermostat to replace the dial then i can tell it what time to kick in with what preset temp,

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• EvertonHero
• 7 Feb 2012
• 1

OLD WIRING

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• EvertonHero
• 7 Feb 2012
• 1

NEW WIRING

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• EvertonHero
• 7 Feb 2012
• 1

from what you can see in my new wiring setup I have the live in C & the switch wire in A the N is in a choc block & so is the earth in a seperate one,

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• EvertonHero
• 7 Feb 2012
• 1

The problem i have is when i put the power back with this new setup the boiler will just keep running on its own and doesnt take any notice to what is set on the new one or even the one below it,

so i tried swapping the live & switch around but still makes no difference

but take it all apart but my old thermo on and its all good again


Sorry for rabbiting on thank you all for any advice you give me,

Cheers,

Will

 

[ChrisR]

Almost impossible to follow ..!

How about you tell us what boiler you've got and we'll tell you what wires should go where?

If your wires were wrong before, we can't start from that

 

[EvertonHero]

i know im sorry im all over the place myself...


Here is my boiler info...

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• EvertonHero
• 7 Feb 2012
• 1

right ill start from before i got the new programmer and you can see if theres any problems here.

to turn the heating on inmy house we have to turn the dial up (above 15') then the blue light clicks on and then you can hear the boiler kicking in,

to turn the heating off we have o turn the dial below 15' again clicking the blue light off..

which is all good and well but if we want to set the heating to come on say 30mins before we are awake it wont, because the dial is still just under 15' so it wont get hotter than that!?

The hot water timer works spot on weve always had hot water no issues

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• EvertonHero
• 7 Feb 2012
• 1

we always have HW on timed & CH on off...

so to "fix" this situation I tried to install the new programmable timer to let me set dif times/temps etc but when ive swapped it over the boiler is just running continusoley no matter what settings are in place!?

hope this makes more sense,


Thanks again,

Will

 

[D_Hailsham]

My old thermostat was just a dial to set the temp,1st problem/situation is no matter what was set on the clock under the boiler for CH off/timed/on etc it would not effect any of the house temp unless this dial has moved.

That's what is supposed to happen. The boiler can only come on if the clock is in an ON period, but the boiler will come on only if the clock is in an ON period and the room temperature is below the temperature set on the thermostat.

which is becoming a pain waking up & coming home to a cold house every day

The Potterton Timer has two ON periods a day (select the "timed" setting), so you could set the first period for the morning and the second for the evening, with the boiler coming on before you get home.

 

[EvertonHero]

ty for the quick reply D_Hail,

so if i want to wake up in a house set at 30* ill set the timer to say 5.30 - 6.30am

but as soon as i turn the dial upto 30* it will kick in straight away when i dont want it to,

and if i leave the dial on 15 and the boiler kicks in at 5.30 its not going to go any higher than 15 which is no good still?

sorry if im missing soemthing obvious out here but i just dont get it!?

 

[denso13]

Connect the new stat using A and B, not A and C

 

[patsmotors]

as long as the system is correctly wired (systems can be incorrectly wired but work in a certain fashion).
15 c temp is low very low espicially if you have an insulated property and location of thermostat including external heat sources.
wire your new thermostat A-B as per denso,if all else fails you need a heating engineer with experience or wiring.not a parts changer.
ensure a 3 amp fuse is used.

 

[D_Hailsham]

so if i want to wake up in a house set at 30* ill set the timer to say 5.30 - 6.30am

and if i leave the dial on 15 and the boiler kicks in at 5.30 its not going to go any higher than 15 which is no good still?

Both examples are normal behaviour. The thermostat sets the maximum temperature you want in the house. So if you set it to 15C for 5.30, that's what you will get.

but as soon as i turn the dial up to 30* it will kick in straight away when i don't want it to,

sorry if im missing something obvious out here but I just don't get it!?

Maybe I am missing something!

Do you mean that the system is ignoring the timer completely, so you have to turn the temperature down to 15C when you go to bed and back up to 30C (an example, I hope ) when you get up?

If so the existing wiring is incorrect. The thermostat should only turn the boiler on when the timer is in an ON period or on permanently.

 

[warmadmax]

the original setup sounds like it was doing what it was designed to do,

timer on front of boiler says in what times the boiler could turn on,
Nothing to do with temperature, just the time windows it can operate in.

The thermostat telling the boiler it needed to come on to raise the temp and when it needed to go off again.



Not seen a manual for your programmable stat, but if you can tell it different temp's for different times of day, it should be able to do what you want.

 

[EvertonHero]

Ty all guys,

So if i turn my dial upto 30* no matter what the boiler programmer is set to it will turn on the heating, so even if i programme the timer to come one for 1 hour a day as lon as that dial is on 30 (or anything above 15) the heating wont turn off... So i cant set it to turn on at a desired temp?!?

I havnt tried the wires in a&b yet i will when i get in, iv been in touch with a local lad i know whos arranging to pop down and have a look cos its getting to cold in the mornings now and the mrs suffers with reinards!!

 

[warmadmax]

no what should happen on the old setup is this...

stat set to 30c + heating timer off = boiler off
Stat set to 30c + heating timer on = boiler on till it hits 30c & relights as required to maintain it

stat set to 15c + heating timer off = boiler off
stat set to 15c + heating timer on = boiler on till it hits 15c & relights as required to maintain it

if that's not happening then you've got wiring issues, which could be the programmer has been taken out the loop and the boiler is only talking to the thermostat.

with your programmable one, it should take over the role of both the thermostat and programmer for the heating, you'd set the boiler programmer to constant and leave it to the programmable stat.

Swap C to B as said above and the stat shoud behave itself.

 

[EvertonHero]

Thank you all,

simply enough on my dinner today i did a quick change over and moved wire C into B and kablam it sorted it,

I have no preset 4 different times per day over a 7 day week and come home to a toasty warm house for the 1st time in a long time.

Thank you all for your help on this i know its hasnt been a simply one to start off with!

Many thanks again,

Will

 

[sunnie]

he will be back soon.