Heatmiser room stat

[nod]

Just gone into a room we don’t use much and noticed the room stat is totally blank 

Any ideas where to look Or am I looking at a new stat 

[nod]

59 minutes ago, nod said:

Just gone into a room we don’t use much and noticed the room stat is totally blank 

Any ideas where to look Or am I looking at a new stat 

Just swapped the stats round and it works in another room

Replacement actuator ?

Edited December 25, 2019 by nod

[nod]

 

[Temp]

Did you try a known good stat on the suspect location?

 

Perhaps no power to that stat position? Caution some Heatmiser stats are 12V and some 230V.

 

See if there are model numbers on the back. Google and download the manual which have wiring diagrams. Check which pins should have power on them.

 

 

Edited December 25, 2019 by Temp

[nod]

11 minutes ago, Temp said:

Did you try a known good stat on the suspect location?

 

Perhaps no power to that stat position? Caution some Heatmiser stats are 12V and some 230V.

 

See if there are model numbers on the back. Google and download the manual which have wiring diagrams. Check which pins should have power on them.

 

 

Yes thanks I’ve just tried that 

moved one that was working showed no display at all

I replaced it with the one that was blank and it worked fine 

I’m guessing no power to the first location 

I’m not sure what would govern that Faulty actuator? 

[dpmiller]

power comes from the wiring centre.

[nod]

6 minutes ago, dpmiller said:

power comes from the wiring centre.

Yeah I did think that 

Im at a loss as to why it would just go blank

 

[vfrdave]

@nod did you move the faceplate and the backing plate? I know my 12v ones are 2 part.

 

As @dpmiller says power comes from the wiring center and is independent from the actuator.

[nod]

I’ve taken the back box off and I think the problem could be at the back of the stat 

voltage free switch 

Replacing that looks a good start point 

[nod]

2 hours ago, vfrdave said:

@nod did you move the faceplate and the backing plate? I know my 12v ones are 2 part.

 

As @dpmiller says power comes from the wiring center and is independent from the actuator.

Sorry didn’t read this before posting 

Its the back plate that is faulty 

Thanks all for taking the time to answer 

Edited December 25, 2019 by nod

[stearman65]

Hi All

I have 2 Heatmiser & 2 Maincor stats on my system. What do you set the 3 position switch on the side to for normal daytime operation. My switch says UP for constant, centre for set SET BACK & down for OFF. Does anyone know if the CONSTANT position the 'stat still opens & closes. They are all connected to a Heatmiser UH3 wiring centre & a Maincor programmer.

[Temp]

 

5 hours ago, stearman65 said:

Does anyone know if the CONSTANT position the 'stat still opens & closes.

 

Short answer is Yes. It opens and closes so the set temperature is maintained 24/7. It does not mean the burner in the boiler runs 24/7.

 

I think there have been several (3?) versions of that stat. This looks like the manual for one of them..

 

https://www.heatmiser.com/en/download/211/english/11237/heatmiserds-sb.pdf

 

The slide switch is described on page 2. It has three positions..

 

1 = ON

Stat ignores any Time Clock and controls heating all the time, turning it on and off as necessary to maintain the set temperature 24/7.

 

Clock = Set back mode

This mode uses a separate clock that either sends 230V to the stat (Daytime) or doesn't send 230V (Night time).  When the thermostat receives a 230v signal from the time clock the stat will control the temperature according to the dial setting. When no 230v signal is received from the time clock, the thermostat will operate in setback mode and automatically reducing the set temperature by 4°C. So if set to 21C the room should be heated to 21C in the daytime and 17C (21-4=17) at night time.

 

0 = OFF

Heating OFF. Stat does not control the room temperature.

 

5 hours ago, stearman65 said:

What do you set the 3 position switch on the side to for normal daytime operation.

 

The best setting IMHO would be to leave it in Clock/setback mode all the time but make sure the clock is set right... 

 

I would set the clock so that night time/setback mode starts about an hour before bedtime and finishes an hour before I get up.  I say "an hour before bedtime" because it takes the house awhile to cool down (eg it should still be warm when you go to bed). If you find the house too cold just before bedtime then reduce this time from 1 hour to say 30 mins. I say "an hour before I get up" to give time for the house to warm up (eg so its 21C when I get up). If you find the house hasn't reached the target temperature (21C) when you get up then increase this time so it has more time to warm up.

 

If you have a party that goes on late into the night then you might consider switching it to position 1 (ON) but next day put it back to clock/setback.  

 

[stearman65]

Hi Temp

Thanks for the reply. Yes that is the instruction for my Heatmiser 'stats. I was writing a long list of possibilities why my heating isn't performing yesterday, how I want it to. I already had a copy of that one & in re-reading it yesterday came across the statement "and will continuously control to the set temperature." in the up position, It just hadn't sunk in when I read it weeks ago. It was the agents engineer's statement that all the 'stats should be in the set back mode after he'd had a conversation with Maincor that led to them being set incorrectly. I set 3 of them to the top position yesterday afternoon & they all controlled at the set temperature.

What doesn't happen, at night if I put them back to the set back position, the boiler still cycles through the night. I have a medical condition called rhinitis, which if there is any sort of heat in the bedroom, my sinuses dry out & causes problems with breathing. Worcester Bosch do a mechanical clock, the MT 10 which would fit in the blank panel in my boiler, that I could set it so the boiler goes off at midnight & comes on at 6am, 2 hours before I normally get up. The local WB man can supply & fit one for £120, I've put that to the agent, saying I would pay, but he has to get the landlord's permission.

Sorry for the long explanation, now we've proved the 'stats will control through the day, it's a step in the right direction

The only problem then is finding why the boiler pressure loses pressure gradually over 2 weeks & has to be re-pressurised.

Regards & thank you.

[Temp]

Yes on setback the boiler will probably switch off for an hour or two at night then may fire up again to maintain the setback temperature. 

 

In the winter indoor air can be very dry so you might find a humidifier helps more than reducing the temperature more than the 4C that the set back provides.

 

4 hours ago, stearman65 said:

The only problem then is finding why the boiler pressure loses pressure gradually over 2 weeks & has to be re-pressurised.

 

Check if any water is coming out of the pressure relief valve? Or from DHW header tank overflow?

[stearman65]

2 minutes ago, Temp said:

 

 

 

Check if any water is coming out of the pressure relief valve? Or from DHW header tank overflow?

The PRV & expansion tank have been changed by WB, the agents engineer fitted a balloon on the PRV outlet twice, first time it inflated & the tank & PRV were changed. As of now the static water pressure has dropped below 1 bar in a week from re-pressurising the balloon is flat, no sign of inflation. WB says re-pressurise if below 1 bar. I believe the DHW header is connected to the sink outlet & can't be seen or checked, if that is the reason, do you know how it can be checked. Are you referring to my Worcester Bosch Greenstar 32 compact? Haven't seen anything about that in the user guide.

Thanks Stearman65.

 

Greenstar_CDi_Compact_Combi_ErP_Operating_Instructions_(1).pdf

[Temp]

Sorry forget I mentioned DHW header. I was having a brain fart. 

 

 

[stearman65]

10 hours ago, Temp said:

Sorry forget I mentioned DHW header. I was having a brain fart. 

 

 

No probs, we all have those at times.

Done some more research today, found the WBosch say maximum outlet temperature at the boiler, 50C for UFH.

Also mine has a Heatmiser UH3 wiring centre & the clock they've fitted is the wrong one according to the wiring diagram. TC-02 fitted, should be TM4-TS. Also looks like they've wired the TC-02 wrong & that's why the boiler cycles all night.

Reg's Eric.

Maincor_TC-02_Instructions_(1).pdf TM4_TS.pdf Heatmiser-UH3-Wiring-Centre.pdf

Edited March 2, 2020 by stearman65
typo

[Temp]

 

2 hours ago, stearman65 said:

the clock they've fitted is the wrong one according to the wiring diagram. TC-02 fitted, should be TM4-TS

 

I might be wrong but i believe the difference is minor. The TC-02 is a single channel time to clock and the TM4-TS is a four channel. I believe the time clock shown on the UH3 wiring diagram only controls the setback time. So does it matter if all stats switch from normal temperature to setback temperature at the same time (TC-02) or in groups at different times (TM4-TS)? I suppose some people might want to setback different rooms at different times but you are after the ability to turn off bedrooms totally not just setback.

 

One solution would be to replace the stat in your bedroom with a fully programmable stat. That would allow you to program it to be fully off at night not just set back. The boiler might fire up to heat other rooms but yours would be off.

 

We have Heatmiser programmable stats and you can set the temperature to at least four different values at different times. Eg you could set..

 

Waking up temperature (20C)

Daytime temperature (18C)

Evening temperature (22C)

Night temperature (10C or lower so it's effectively off, just acting as a frost stat).

 

You can also alter the times it switches between these temperatures.

Edited March 2, 2020 by Temp

[stearman65]

Hi Temp.

This is a rented apartment & I can't do anything without the agents say so. IMO the only thing that needs correcting is to alter the connections in the clock. I haven't seen how the TC-O2 on my system is wired, but I do know when the guy  installed it he added the optional link. If you look at terminals 4 & 5, one is normally open & one normally closed. I think these two connections are the key why the boiler cycles all night, one of these is on the wrong terminal. The clock reads on & off at the correct days & times, it  just doesn't switch off the boiler when the clock reads off. I just don't have the b***s to whip the front off & switch the wires in case I blow the whole shooting match or lose the current settings.

Regs Eric.

Maincor_TC-02_Instructions_(1).pdf

[Temp]

Ok after another look I can't tell from your original photos of the stats which of the following modes the system was designed to operate in..

 

1) The clock determines if the stats are in normal or setback modes. 

or

2) The clock turns the whole system on/off (and the stats are wired permanently in normal temperature mode).

 

You would need to figure out if the time clock is controlling the clock input on the stats. The manual for the stats says that (with the switch in the clock position)..

 

https://www.heatmiser.com/en/download/211/english/9550/ds-sb-v3-2.pdf

 

When the thermostat receives a 230v signal from the time clock it will control the temperature according to the dial setting. When no 230v signal is received from the time clock, the thermostat will operate in set back mode and automatically reducing the set temperature by 4°C

 

If that's how your system was designed to work then I would expect the boiler to wake up in the night sometimes, probably several hours after the clock switches off and the temperature drops 4C below the set temperature. 

 

However if the clock inputs to the stats are permanently live then the clock might be intended to turn the whole system on and off (and it has a fault or wiring error that prevents it turning off at night).

 

1 hour ago, stearman65 said:

I do know when the guy  installed it he added the optional link.

 

I believe the optional link on the clock just converts the relay output from "volt free" mode to "Switched 230V"  mode. 

 

1 hour ago, stearman65 said:

If you look at terminals 4 & 5, one is normally open & one normally closed. I think these two connections are the key why the boiler cycles all night, one of these is on the wrong terminal.

 

I would expect only one to be connected to the UH3, probably the NO output. If more than one has a connection where does it go?

 

 

[stearman65]

5 hours ago, Temp said:

Ok after another look I can't tell from your original photos of the stats which of the following modes the system was designed to operate in..

 

1) The clock determines if the stats are in normal or setback modes. 

or

2) The clock turns the whole system on/off (and the stats are wired permanently in normal temperature mode).

 

You would need to figure out if the time clock is controlling the clock input on the stats. The manual for the stats says that (with the switch in the clock position)..

 

https://www.heatmiser.com/en/download/211/english/9550/ds-sb-v3-2.pdf

 

 

 

 

If that's how your system was designed to work then I would expect the boiler to wake up in the night sometimes, probably several hours after the clock switches off and the temperature drops 4C below the set temperature. 

 

However if the clock inputs to the stats are permanently live then the clock might be intended to turn the whole system on and off (and it has a fault or wiring error that prevents it turning off at night).

 

 

I believe the optional link on the clock just converts the relay output from "volt free" mode to "Switched 230V"  mode. 

 

 

I would expect only one to be connected to the UH3, probably the NO output. If more than one has a connection where does it go?

 

 

You must be burning the midnight oil?

The SET BACK mode is a manual operation by the user from the 3 position switch on the side of the 'stat, 1. switch at top constant, 2. mid position set back, 3. bottom position off. Pictures attached taken last night before I went to bed & this morning. 'Stat pic, switch in set back mid position. Note boiler pressure down to .6 bar last night, just above the fail pressure.

Reg's Eric.

[Temp]

Humm, see what you mean. Doesn't look like setback is working. Lounge should probably have fallen to perhaps 16-17C by 5.45am - unless the place is very well insulated.

 

Did you notice which if any LEDs on the lounge stat were illuminated?

 

Right hand LED should be yellow if its correctly in setback mode (and not calling for heat). Left hand LED either on or off depending if its calling for heat or not.

 

 

 

 

 

 

 

Edited March 3, 2020 by Temp

[stearman65]

54 minutes ago, Temp said:

Humm, see what you mean. Doesn't look like setback is working. Lounge should probably have fallen to perhaps 16-17C by 5.45am - unless the place is very well insulated.

 

Did you notice which if any LEDs on the lounge stat were illuminated?

 

Right hand LED should be yellow if its correctly in setback mode (and not calling for heat). Left hand LED either on or off depending if its calling for heat or not.

 

 

 

 

 

 

 

Hi Temp

The set back does work using the switch & the LEDs change, but the difference in temperature  fluctuates between 4 & 10 degrees in the rooms I have thermometers in, which is why I don't want to use it but just have the boiler switch off between midnight & 6am 7 days per week.

Regs Eric.

[Temp]

I think you will have to get someone locally to look at it.

 

If setback is actually working (eg putting the switch on the stat to the Clock position reduces the temperature at night by 4C)  then the Clock must be controlling setback mode in the stats. Either that or the manual is wrong. That's because manual for the stat says...  

 

To make use of the set-back function, a 230v time clock is also required on the system

 

If you want the clock to turn off the heating totally instead then it will need to be rewired.

 

I think it should be possible to add a two position switch that is labeled "Setback" and "ON/OFF". In one position the Clock would put it into setback at night (as now) and in the other it would turn it OFF totally at night.

 

 

[stearman65]

The boiler went pop again last night, up until 2 getting it re-pressurised & writing the agent a snotty letter. Worcester Bosch coming on their 5th visit since new years eve on Friday. Put a show together on youtube see the link. Started to look for another home, don't think they'll ever fix this one.

https://www.youtube.com/watch?v=VhckWso6z7U