Do Optimum Start Thermostats Work?

[gas4you]

All the ones I have removed have been due to going faulty, all Honeywell CM67's, all with exactly the same fault.

Now don't bother.

Easier life.

 

[mickyg]

All the ones I have removed have been due to going faulty, all Honeywell CM67's, all with exactly the same fault.

Now don't bother.

Easier life.

whats the fault dave? i've been changing a few Dt90s lately with faulty relays, wondered if its same problem?

 

[Agile]

The cheapest I have found online is over £40.

I dont think you looked very hard!

This one is £14 + VAT if you buy 100 or £20 + VAT if you just get one! Note the batters is shown as non replaceable but I would aim to get inside and sort that out!


Measurement Range -40°C to 85°C
Resolution < 0.1°C for -40°C to +40°C
< 0.2°C for 40°C to 80°C
Accuracy Better than ±0.5°C for -10°C to +40°C
Better than ±0.7°C for -10°C~ -30°C & +40°C~+60°C,
Better than ±0.8°C for -30°C~ -40°C & +60°C~+80°C
Sensor Reaction Time Typically less than 5 minutes (T90) in moving air.
Capacity 8000 Readings (16000 bytes Memory)
Sampling Frequency Adjustable, 30 seconds to several hours.
Recording indication Flashing 'OK' indicator and flashing 'Alert' indicator.
Download Time Typically with full memory (8000 readings) in less than 5 secs depending on computer or readout device used.
Standards Compliance IP65 (Total Protection against dust and low pressure jets of water from all directions - limited ingress permitted)
Power Source 3V Lithium Battery - Non-Replaceable
Battery life 2 ~ 3 years of normal use (based on 15 minute logging, download data monthly)
Software Windows 32-Bit Vista and XP Compatible
Size 86mm(H) x 54.5mm(W) x 8.6mm(T)
Weight 35g
Case Material Polycarbonate
EMC Compliance Tested and complies with EC EMC directives (EN 50081-1:1992 & EN 61000-6-1:2001)
EN12380 Compliance Tested and complies to EN12830:1999 for transport, storage and distribution of chilled, frozen, deep frozen, quick-frozen food and others.


The one I use is a USB-501-LT by Measurement Computing.

Tony

 

[D_Hailsham]

The cheapest I have found online is over £40.

I dont think you looked very hard!

This one is £14 + VAT if you buy 100 or £20 + VAT if you just get one! Note the batters is shown as non replaceable but I would aim to get inside and sort that out!

The one I use is a USB-501-LT by Measurement Computing.

Who did you buy it from?

The cheapest online price I have found for that model is £45.

 

[Agile]

I obtained mine directly from the promoters as an evaluation sample to determine its usefulness in setting up heating and weather compensation systems.

They are ideal. I dont know why more heating engineers dont use then.

But the listed one is cheaper.

Tony

 

[gas4you]

All the ones I have removed have been due to going faulty, all Honeywell CM67's, all with exactly the same fault.

Now don't bother.

Easier life.

whats the fault dave? i've been changing a few Dt90s lately with faulty relays, wondered if its same problem?

Every single one would not bring the heating on first thing in the morning.

Every other on and off command worked fine

It always seemed to happen after about 4 months or so.

 

[mickyg]

All the ones I have removed have been due to going faulty, all Honeywell CM67's, all with exactly the same fault.

Now don't bother.

Easier life.

whats the fault dave? i've been changing a few Dt90s lately with faulty relays, wondered if its same problem?

Every single one would not bring the heating on first thing in the morning.

Every other on and off command worked fine

It always seemed to happen after about 4 months or so.

strange, not the same thing anyway. cheers. at this rate im gonna go off honeywell controls!

 

[D_Hailsham]

I obtained mine directly from the promoters as an evaluation sample to determine its usefulness in setting up heating and weather compensation systems. But the listed one is cheaper.

Intereresting info, but it does not answer my question.

Where can I buy one from for £20?

 

[Agile]

I think it was an advert by datashop which came up on Google search for 'USB data logger'

essential tool for setting up W/C for a heating engineer.

Tony

 

[MJN]

I will report my findings when the heating goes on.

Did you ever get round to deploying this test? If so, any findings to report..?

Mathew

 

[mikely]

Anyone who cares about their house being at a certain temp at a certain time will get to know their system and time the programmer as such. The difference in different temp environments in domestic premises is negligable (it might take 20mins longer when its really cold---big deal). I can imagine in a very large house or commercial premises it makes more sense.

In my experience (using a Honeywell CM907) during this recent cold weather the heating starts 2 hours before set time because it does take that long to heat up, even with a night set-back temperature of 13C. In milder weather it may be only 30 or 40 mins. So, yes, it does work.

On the subject of data loggers, I think this is the one I bought:
http://cgi.ebay.co.uk/Laptop-Notebo...deo_TelevisionSetTopBoxes&hash=item4aa69edafe

 

[D_Hailsham]

I will report my findings when the heating goes on.

Did you ever get round to deploying this test? If so, any findings to report?

Yes. The test has been running since 17 September. On times definitely vary with outside temperature - though I have not got a definite relationship. The minimum I have seen is 15 minutes and the maximum two hours in the current weather. I don't have data for every day, as sometimes I forget to turn the timer on when I go to bed.

 

[MJN]

Thanks for that. The reason I asked is that from my limited, and admittedly crude, testing I oftentimes found the stat to err on the side of caution somewhat.

Specifically, it seemed to reach target temperature way too early - nearly an hour in once case I seem to recall. I can accept it can't be perfect but that was pushing it a bit. To be fair, the testing was far from structured and so it could well have been the case that there was some other factor at play e.g. several days of the house being cold due to fitting windows, or the boiler being out of action due to plumbing works but me not 'telling the stat'. Both cases could lead to the stat thinking the heat-up times were significantly longer than reality.

I might give it another chance but this time paying a bit more attention to performing a fair test.

maximum two hours in the current weather

I seem to recall that's the maximum it'll do, compared with the previous CM67 which could come on upto 3hrs prior.

Mathew

 

[D_Hailsham]

Specifically, it seemed to reach target temperature way too early - nearly an hour in once case I seem to recall.

I've never checked this as I don't feel like getting up at 0530 to see if the house is up to temperature.

I can accept it can't be perfect but that was pushing it a bit. To be fair, the testing was far from structured and so it could well have been the case that there was some other factor at play e.g. several days of the house being cold due to fitting windows, or the boiler being out of action due to plumbing works but me not 'telling the stat'. Both cases could lead to the stat thinking the heat-up times were significantly longer than reality.

I know the stat "learns" when to come on, but I'm not sure if this is a one off task or a continuous learning process. Is there any way of telling the stat to start again, for example after you have installed insulation?

maximum two hours in the current weather

I seem to recall that's the maximum it'll do, compared with the previous CM67 which could come on up to 3hrs prior.

I must say that I am surprised that it takes 2 hours to heat the house each morning as the house is very well insulated (filled cavity walls, 270mm in loft and DG windows), the internal temperature only drops about 5 or 6 degrees overnight (stat set to 5C overnight), and the rads and boiler are now massively oversized for the heat loss.

 

[MJN]

I've never checked this as I don't feel like getting up at 0530 to see if the house is up to temperature.

Indeed. I seem to recall I caught by just happening to be nipping to the loo at that time.

I know the stat "learns" when to come on, but I'm not sure if this is a one off task or a continuous learning process.

I think it would have to be continuous otherwise there would be a very real risk of it being incorrect if it was a one-off and, as you mention, there's no readily available (documented) means to make it re-learn.

I must say that I am surprised that it takes 2 hours to heat the house each morning as the house is very well insulated (filled cavity walls, 270mm in loft and DG windows), the internal temperature only drops about 5 or 6 degrees overnight (stat set to 5C overnight), and the rads and boiler are now massively oversized for the heat loss.

Could it be that yours too went a bit overboard and ended up reaching target temp way too early? It would certainly correlate with my findings (notwithstanding by limited testing as previously mentioned).

Mathew