EQ-3 Radiator Thermostat Model M

Our kitchen, my wife's external study and my external room all come under the same Honeywell room stat, but each requires independent control. The standard mechanical radiator stats where simply not up to the job, so decided to try these EQ-3 electronic Rad Stats. They are a third the price of the better known brands, and wondered if they would work as well, but needn't have worried.With a standard fitting, these are very easy to install, just unscrew the old valve and screw on the new one. To get them working, pull out the battery isolation tab, that otherwise prevents the battery connection. It is easier to set the time and date before installing the valve. The display then shows INS (install) and it rewinds to plunger so the valve can be installed. After installation then press the control knob to start the ADAPTION (AdA), which takes a few minutes. I then pressed the Mode/Menu button to select Manual operation, then turned the knob to set the required temperature.I then decided to log the temperatures related to the kitchen, using four "Elitech URC5 USB High Accuracy Temperature Data loggers". These recorded the temperatures by the room stat, by the radiator thermostat, outside and on the radiator.The room stat was about 3m from the radiator and about waist high. This was set well above the room temperature, so had no effect on, or control over, the room temperature. Radiator and its stat are behind a settee, but this has space under it to allow air flow to the radiator and its control stat.The temperature logging started about 3pm and ran for about 70hours, with the valve temperature set to a constant 19C. At the end, all four loggers were brought together by the room thermostat, to all equilibrate to the same temperature for about four hours, to verify they were all reading the same temperature, within acceptable limits, which they were.The results of this temperature logging is show in the picture.The average temperature of the Rad Stat was 19.1C, within 0.1C of the set temperature, and for about 95% of the time (+/-2 standard deviations) was within 0.5C of the set temperature.The average room temperature was 20.3C, or 1.3C warmer than the Stat setting, and for 95% of the time was within +/- 0.65C of this average.The typical valve cycle time was about 2 hours, though this may depend on the size of the room and particular conditions. The smoothed temperature of the radiator was pretty much a mirror image of the outside temperature, but perhaps delayed by an hour or so.The various peaks in the room temperature can be attributed to solar heat from the Sun, during the morning, or heat from an electric oven, used to cook lunch.So far very pleased with these electronic Rad Stats, much better than the mechanical ones. Haven't tried any of the more complicated time controls, as they seem rather more complicated to set. Also the clock will have to be changed twice a year. So for now will just use them on manual control.What I really like is that it is now possibly to properly control the room temperature, without wasting heat when it is uncomfortable hot, or shivering unnecessarily when it gets too cold. I now know I can just set the required temperature, allowing for the expected offset, and know I will get that.I understand the battery lasts about 3 years, but presume that depends on how much controlling the valve has to do. I understand that when the battery is changed, the valve reverts to its factory settings and date and time have to be reset.Very good temperature control and very good value for money.

This worked but makes a whirring sound when operating and woke us up in the night. Had to send it back

Potentially massive savings and its made a huge difference. I am quite excited with the result so far. Not only has the room temperature remained more regular but you can hear a gentle whir as it opens or closes so you know when it's actually doing its job. The sound is not annoying and the room has remained constant enough anyway. We actually have a very costly heating system, a rented house with a woefully inadequate small combi boiler. The house is very old with gaps in doors and windows. We blow £50 a week in the deepest winters on gas as our insulation is so poor. This has been on for 4 days and if my calculations are correct, it's possibly going to save £5 a week. How is that possible it seems too good to be true.They seem particularly useful for spread out houses with rooms that have little impact on each other heat wise. I fitted our first on the largest room 5mtrs x 4mtrs which needs to keep an elderly person warm some of the time so is the most expensive one in the house. I can't comment further on how useful or necessary they would be in a smaller closer together building. We are high on the hills so heating is a huge expense to us. If this makes the savings it's designed to I am going to be very happy indeed. I will return with an update when I've tested the other two I've just ordered and the first one a little more. The LED screen is big and wheel is easy to use and so far I've not set the timers I've just moved the dial up and down till the room became perfect at 17.5 I shall set the timers once I've watched it work for a little longer.Update 1 week of use on 1 radiator. Calculations showing a saving on our meter of 10p an hour. Suddenly that room we couldn't afford to heat is a pleasant warm constant temperature and mum can read the dial and turn it up or down if she needs to.We are sum what blown away. I've bought 2 more which I will fit this week and fill the meter again. Then keep a log of the amount left for another week. How are these things not used as standard on central heating systems I don't know and why didn't I hear of them before. Brilliant for a draughty big spread-out old house.I did not realise that the 1to5 usual thermostats on the radiators do not intelligently turn the radiator on or off, they just pump out the heat a courting to what you've set the dial at. These digital thermostats actually sense when the rad needs to work and when it doesn't and switches it on and off. I am so happy we will do the whole house.

insructions poor and little chance of using

This arrived quickly and once unpacked I found it really easy to set up.I programmed it before I installed it as I figured it would be easier but it's just as easy on the radiator.Once programmed I removed the current trv and this screwed straight on in its place, I pressed the button to get it to run its initial set up program and within a few minutes it was ready to go.It's very quiet, I havent noticed it running at all, but it's working beautifully.It has a child lock too which is really useful in a household of small, inquisitive fingers.I've ordered more for the other radiators in the house

brilliant (so far) I purchased this to replace a failed Honywell unit. the Honywell rondostat unit is ok when working but fatally unreliableI originally purchsed three Honywell but all have benn replaced under warranty with all three replacements now failed.The Salus unit is awkward and confusing to install and program the screen is upside down when installed.The EQ-3 unit is comparatively straitforward to program and has easy to read conveniently angled screena bonus is the batteries can be changed without removing unit from radiatorThe price is modest and it It works well. I reserve right to comment later on reliability in light of long term experience.

Although it would fit my standard radiators in both work and at home there is very limited movement in the control pin that pushes the spigot in the radiator valve therefore would not fully close off the radiator. Will buy a quality one next time. See pics for open and closed range of movement.