Recommendation for new thermostat

[Miss_e101]

Hello,

I would like to replace my old analogue thermostat with a programmable digital one. My first attempt failed as the unit I bought was not actually a thermostat, just a timer (d'oh!) so I am looking for a recommendation from people who know better than I.

The old thermostat was a Honeywell t40 - just a simple dial one. My boiler is a vaillant ecotek plus 832 R1 condensing combination boiler.

I am looking to spend no more than £30, if possible.

Any advice would be greatly appreciated.

Cheers,
Miss_e


Read more: //www.diynot.com/diy/threads/replacing-boiler-thermostat.444942/#ixzz40Fv0az5r

 

[Taylortwocities]

Programmable digital thermostat for less than £30? You'll probably need to spend a bit more than that.

Why do you need a programmable one, does the boiler not have a programmer built in?

The Digistat 3 is a fairly low cost one with a good range of features. £52 including the dreaded.

 

[EFLImpudence]

There are cheaper ones on Amazon but I don't know how good they are.

 

[Echo the husky]

Salus are awful! I'm fed up with replacing their faulty stuff. You'd be better off keeping the Honeywell mechanical stat! Honeywell is where I usually turn to.

 

[Taylortwocities]

Salus are awful

I'll only recommend something I have used and can trust.

 

[Iggifer]

I'd vote for the CM907 too. Bit cheaper on the old fleabay, but still >£30

 

[Echo the husky]

Why do you need a programmable one, does the boiler not have a programmer built in?

Do answer this though. If you just want a digital thermostat (without programmable times) then the Honeywell DT90E is a good option that is compatible with your wiring.

 

[Miss_e101]

Thank you all for your advice. I want the programmable one so that I can set it to operate differently depending on the day of the week (i.e. low when I'm at work and regular on the weekends).

£30 may have been a bit too optimistic, but the Drayton looks like a good choice.

Thanks again.

Cheers. =)

 

[ericmark]

At home I am using the old version of the Horstmann DRT2 also used in narrow boat and daughter also uses the same. It does 4 temperatures for week days all at same time and 2 temperatures Sat and Sun times can differ. It has been used for around 8 years the only problem found is the batteries go too flat to work relay before the battery warning light comes on. Batteries last about 2 years but I now change every year so not caught out. Less than £25.

At my mothers house I use a Horstmann HRFS1 which is wireless it can be set like the DRT2 or you can set 7 separate days. It can be wall mounted or placed on furniture I had some teething problems where it had quite a large slewing range but simply placing closer to radiator got rid of that, it has 6 temperatures per day. More expensive at under £60.

As you move to more expensive thermostats they have a learning capability and can auto adjust the slewing range (the difference in temperature from switching off and switching on) although the thermostat may be set to 0.5°C it takes time for the heat from radiator to reach the thermostat so one gets a hysteresis mothers house it would vary between 21°C and 25°C with the thermostat remote from radiator but 23°C and 25°C when near the radiator measured with the remote camera. It was more down to radiator size than thermostat one radiator got hot it took time for the heat to reach thermostat and when turned of heat is still coming from the radiator so room getting hotter. Some of the expensive types learn about this and compensate.

It may seem odd but best place for thermostat is near radiator when that happens, it's all down to design of house. The Honeywell Evo home kit is really the bee's knees here but real expensive however there are some programmable TRV heads which are far cheaper so you instead of switching all heating on and off you treat every room independently. So bedroom only heated at night for example.

The problem with all the devices other than the Honeywell Evo home is they are in conflict with each other a radiator thermostatic valve (TRV) can only heat a room if the central heating is running so without a link between TRV and the main controller it is a bit hit and miss. Even wind direction can change which room is the warmest.

With mothers house we considered the Honeywell Evo home and I thought it cost too much. So the new Horstmann HRFS1 controls living room in the day and the old system controls bed room at night. But I only have two rooms to worry about. My house is open plan so it was designed from day one to work with a single thermostat. The whole idea of running in the day and switched to emergency temperature at night will work where the TRV does the temperature control and thermostat just ensures when off it does not get too cold.

However the idea of 14°C overnight then 20°C in morning then drop to 18°C in the afternoon raising to 22°C in evening seems great, however it is only controlling one area the rest of the house will likely be sitting at the temperature controlled by the TRV. This is why I have two thermostats in my mothers house unless you leave all doors open and have a fan to circulate air a single thermostat simply does not work.

Best compromise I considered was the Horstmann HRFS1 as it can easy be moved room to room. If I win the pools I will get the Honeywell Evo home kit but until then it's leave doors open and the Myson circulates the air.

 

[Taylortwocities]

the Drayton looks like a good choice.

OK, no problemo.

Two things though:
1. If you have a programmable thermostat, you will have to set the boiler timer to be always ON for heating
and
2. The wiring on the T40 will probably have three wires plus an earth, while the digital stat will only have two

there is a guide on how to wire it up in the WIKI, at //www.diynot.com/wiki/Electrics:How-to-replace-a-room-stat
or come back and ask..

 

[Echo the husky]

Miss E has a thermostat wired in twin and earth so no issues there.

 

[Taylortwocities]

Oh, thre's ANOTHER thread with more info. FAir enough, should be a straight swop then.
I still want to know about the answer to my earlier question

Why do you need a programmable one, does the boiler not have a programmer built in?

 

[EFLImpudence]

Even if the boiler has a programmer, that will only be times for on and off governed by a thermostat at one temperature.

A programmable thermostat is needed for different temperatures at different times.

 

[AndyPRK]

Just to point out the Drayton comes in battery or mains version. (blue or red box)

 

[Echo the husky]

Must get the battery version for your wiring.