Help with setting on DT90E stat please..

[xpeterpx]

Just need a bit more advice on what my settings should be after I've installed it following the kind wiring advice here:

//www.diynot.com/forums/plumbing/swap-honeywell-t6360b-dial-to-dt90e-digital.387092/

Finding the instructions provided a bit baffling so wonder if there is anyone more familiar with this stat.

1.I can only seem to have either the on/off symbol or the heat demand symbol displyed with the room temp even though the boiler is off.Should I just have the room temp displayed if the boiler is off?

2.'Set temp inquiry' is set to 5 deg (factory set) should this be different if so what shoudl it be?

3.How do I know what temp setting my boiler will come on at and switch off at ?

Its operating a Vailiant combi boiler in a standard 3 bed house if that helps

Thanks for the ongoing advice.
Pete

 

[D_Hailsham]

1.I can only seem to have either the on/off symbol or the heat demand symbol displayed with the room temp even though the boiler is off. Should I just have the room temp displayed if the boiler is off?

That seems strange. Normally, i.e no buttons pressed, the stat will show the actual room temperature. The boiler should be on if the flame is showing.

Do you have a multimeter, and know how to use it? If so measure the voltage between neutral and terminals A and B (timer on, stat off). If you find that there is 0Vac on A and 240Vac on B it might be worth swapping the wires round and seeing if that has any effect. In theory it shouldn't.

2.'Set temp inquiry' is set to 5 deg (factory set) should this be different if so what should it be?

Do you mean that if you press the up or down button the stat shows 5C?

If so, the stat is set to only turn the boiler on if the room temperature drops below 5C. Presumably you would like the house warmer than that! If so, press the top button until the display shows the temperature you would like, normally 20-21C.

3.How do I know what temp setting my boiler will come on at and switch off at?

One you have set the required temperature the boiler will come on if the temperature drops below the set valve and maintain it to within about half a degree. This is dependent on the heating times set on the programmer/timer.

 

[xpeterpx]

1.I can only seem to have either the on/off symbol or the heat demand symbol displayed with the room temp even though the boiler is off. Should I just have the room temp displayed if the boiler is off?

That seems strange. Normally, i.e no buttons pressed, the stat will show the actual room temperature. The boiler should be on if the flame is showing.

Do you have a multimeter, and know how to use it? If so measure the voltage between neutral and terminals A and B (timer on, stat off). If you find that there is 0Vac on A and 240Vac on B it might be worth swapping the wires round and seeing if that has any effect. In theory it shouldn't.

2.'Set temp inquiry' is set to 5 deg (factory set) should this be different if so what should it be?

Do you mean that if you press the up or down button the stat shows 5C?

If so, the stat is set to only turn the boiler on if the room temperature drops below 5C. Presumably you would like the house warmer than that! If so, press the top button until the display shows the temperature you would like, normally 20-21C.

3.How do I know what temp setting my boiler will come on at and switch off at?

One you have set the required temperature the boiler will come on if the temperature drops below the set valve and maintain it to within about half a degree. This is dependent on the heating times set on the programmer/timer.

Thanks for the quick reply.
On quote 2 regarding the set temp enquiry figure-something not right as I cannot seem to change this parameter at all using the up/down button

 

[D_Hailsham]

On quote 2-I cannot seem to adjust the set temperature of 5 deg by using the up button!

If you don't have it, download the Installer Guide

Enter the Installer mode and check all parameters are as listed.

You can reset to factory conditions by setting Parameter FS to 1.

 

[xpeterpx]

Thanks for the ongoing help.

I've put the old dial stat back on as I'm not happy with not being able to control the new stat as I'd like.

I plan to try again tomorrow with a fresh reset as suggested but what if the same thing happens?
Any thoughts on my actual wiring not being correct or able to accomodate a digital stat?
Looks like the original installer just used standard 3 core.

 

[xpeterpx]

sorry double post!

 

[gas112]

Have you got the batteries in correct or tried new batteries the ones in box may have been laying for a while if not it sounds like a duff stat

 

[xpeterpx]

cheers wil check again

One more question please..
If the set temp for the heating to come on is say 20 deg does the stat maintain the temp at that all the time/constantly until its switched off.

Just curious

 

[D_Hailsham]

If the set temp for the heating to come on is say 20 deg does the stat maintain the temp at that all the time/constantly until its switched off.

The stat will turn the heating on if the room temperature is below the set value and turn it off when it reaches the required temperature. It will then turn the heating on and off to maintain the temperature within about + or - half a degree.

The stat does have a feature call TPI which will cycle the boiler on and off before the set temperature is reached. You can read about it Here.

I was going to suggest new batteries, but gas112 beat me to it. You should always use good quality batteries, preferably Duracell.

 

[xpeterpx]

Excellent thanks.
All up and running now thanks to you guys.
One last thing,this model still clicks on/off for gas demand even though the boiler timer is off.?
Sound normal or have I found my next issue to investigate!

 

[gas112]

Perfectly normal