Using Solar With BM2000 how do i reset the boiler control temp?

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Using Solar With BM2000 how do i reset the boiler control temp?

Post  richardturner10 on Tue Mar 27, 2012 3:50 am

Hi
I am integrating a solar system into my existing BM2000 which I installed new some years ago.
As the BM does not have a solar coil, I am fitting a new thermal store specically for the solar collector, to run along side the BM. I have sized the new (solar) thermal store to regularly 'overheat' in order to transfer the surplus heat to the bulk water of the BM. The easiest way I can see of doing this is to tap into the return radiator line, and run it through a top tapping in the solar thermal store, the overheat temp (the temp the 2port valve and circulation pump will pass water through a top 'overheat' coil) to be set to approx 90 degrees C. In the summer when this will be active more often, the return temp from the BM (which will be the inlet temp to the top of the solar thermal store) will be (on my BM) 77 degrees, as my BM has set this based on what my boiler heating flow supplies to it. I wish to reduce the maximum temperature the BM asks from the boiler, so during the summer, the solar store will transfer its excess heat in a more effcient manner. So I intend to reduce the maximum temp the BM asks for to approx 70 degrees C.
(incidentally the main function of the new solar store is to provide hot water in a pre-heat manner to the BM plate heat exchanger, thus in the summer when this water is hot enough it will pass through the Bm extracting no energy from it. during the winter it will act as a pre-heat and the Bm will only top it up by the minimum amount, thus saving money!)
My question is.....
How do I reset the board in the BM to assess the boiler flow, as it does when it is first commisioned?
If I can re-set this, then I will reduce the boiler flow temp on the boiler, to 70 degrees C (from the current 82)and let the BM assess it and adjust itself accordingly.
Any ideas on how to reset anyone?

Many thanks in advance, Richard

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Re: Using Solar With BM2000 how do i reset the boiler control temp?

Post  mike on Tue Mar 27, 2012 3:54 pm

The ACB can not be altered at all.
I am not up on the solar thing.
But would it not be better to go onto the boiler return?
It may be better to give Gledhill a call.
Mike
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Using Solar With BM2000 how do i reset the boiler control temp?

Post  richardturner10 on Thu Mar 29, 2012 5:53 am

After checking many different documents I seem to have aquired over the years, I may have managed to find the awnser...
It seems the way to re-set the PCB control board is to power down, and insert a jumper link into jumper position 5. When powered up again the PCB performs initialisation checks to confirm correct operation of the board and its connected components, once completed the board should be ready to assess boiler feed temps as per factory re-set. ( I would assume this is well known to plumbers replacing a boiler feeding an existing BM2000)
If this works out not to be the case, an interesting statement in the Gledhill manual does state that during the summer the boiler stat can be reduced for hot water only use, which is the flow temp reduction I am trying to achieve anyway! Hopefully the BM will not be constantly 'calling' for more from the boiler and spinning its ciculation pump.

I would be interested in members comments on how best to connect my solar 'overtemp' circuit into the BM. (as my BM does not have a solar coil).
The aim is to heat the BM using the excess heat from my solay cyl, and I am proposing to do this by connecting in to my radiator return line (switching on and off by a 2 port valve on the inlet to the solar coil) and returning the heated water @ approx. 88-90 degrees C to the BM via the radiator retun line inlet. The existing circulation pump being switched from the 2 port valve wiring when open to circulate this between solar high temp coil and BM. Any ideas if this is the best way to pass heat back to the BM? I was originally intending to break into the boiler feed and return line using 3 port valves on feed and return, but even considering inhibiting the boiler firing when these opened, I rejected this idea and there is a scenario where the boiler is on high fire, when the valves close/inhibit occurs. I didnt wantto take the risk of overheating the boiler in this case.
I have just noticed the towel rail circuit return tapping, any ideas if i can use this as one of my tappings out of the BM? Obviously the flow from the solar cyl into the BM should enter it at low level and out at a higher level on the BM, so it may be possible to use this?

Thanks in Advance

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Re: Using Solar With BM2000 how do i reset the boiler control temp?

Post  mike on Thu Mar 29, 2012 6:11 am

When fitting many of the ACB's.
They are used for different units in some cases.
Some have a code for what ever unit e.g.; A03.
So the idea of the jumper setting is to marry the ACB with the unit it is being fitted to.
Yes of course the boiler stat can be turned down in the summer.
But I see no reason for this when the stores operate around 76c on average.
And yes you are correct the boiler and pump will run to heat the store to it's desired temperature.
I do still think a phone call to Gledhill would be better.
As they may have sorted this out before.
Mike
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Using Solar With BM2000 how do i reset the boiler control temp?

Post  richardturner10 on Thu Mar 29, 2012 6:21 am

Thanks for your prompt reply Mike.
I concurr that jumper settings 1, 3 and 4 do apply to the individual configuration of the BM.
However jumper 5 is OK to use as it is dedicated to performing funtional checks as I mentioned before.
A call to Gledhill may be an option as a last resort, but from memory (even before the extortionate pricing of the calls) they didnt give me a high degree of confidence when anything differed from the very basic of systems.
I would prefer to exhaust the members knowledge on the forum before contacting them. I would assume that integrating solar into a BM2000 has been sucessfully completed somewhere before!
Richard

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Re: Using Solar With BM2000 how do i reset the boiler control temp?

Post  mike on Thu Mar 29, 2012 6:39 am

Yes the jumper 5 is used.
To configure the board to the unit it is been used for.
And checking the settings etc.
60p per minute to the tech guys £6:00p for 10 minutes is not that bad really.
Mike

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Boilermate 2000 boiler control temperatures/ integration with solar sys

Post  richardturner10 on Sat Jun 23, 2012 4:43 am

Hi all
To update how to complete this function (this has now been proven) is quite simple.
If you wish to reduce the temperature your boilermate calls for in the summer (a lower temp is much more economical if you only wish to use the BM2000 for hot water) Then wait until your BM is calling for heat from your boiler (best to wait until this initially calls as you dont want to switch off your boiler once it is hot and firing) then swich off the power to the BM and wait 60 seconds. Reduce the maximum temperature your boiler supplies, and then switch back on the BM2000. Its as simple as that.
What will actually then happen is the BM will re-assess the maximum temperature the boiler can supply, and after some time being supplied with the 'new' maximum temperature, will eventually adjust its parameters accordingly. (mine went from 77max and 74 min to 67max 60 min).
I am sure most people will not be concerned with reducing the temperature during the summer months, as the the max of 77 Degrees C is not massively over the top, but it does has your boiler reaching temps of up to about 88 Degrees C (well mine was - Worchester Bosch 29HE) to squeeze those final degrees in.
It was however important for me to do as I have integrated the previously mentioned solar circuit into it, which is set to transfer excess heat at 77 degrees. This now works much better with the reduced BM temperature, as the transfer differential (77 feeding into 60-67 degrees) is much more advantageous.
One last word, I found the most successful manner to introduce the solar into the BM was to use the evacuated tube collector to heat a seperate thermal store, and then adjust the hot water (DHW) outlet to 56 degrees, then feed it into the BM2000 DHW inlet. The Bm then only acts as a conduit unless extra heat is required (very cloudy days) where it just adds a small amount from its reserves.
The solar store overheats regularly, and i have integrated a secondary pumped circuit into the boiler flow (from the solar store - with non return valves to prevent back flow) and return to introduce this extra heat to the BM2000. I decided (in the absence of any guidance) to pump this excess heat from the top of the solar store, into the flow into the boiler. This permits the excess heat to circulate through the boiler and thus to the BM2000 (with only a minimal heat loss through the boiler exchanger). The advantage of this is that during the winter, if the boiler is firing at the same time, its own controls will safely shut its own firing off without the need for complicated further control gear.
The system works a treat, on a sunny day heating up to 77 then transferring to the BM2000, and heating it then to with the excess heat. The last sunny day, it managed to start transferring at 10:00 in the morning, and then also heating the BM2000 up to 77 degrees also by the afternoon!
I hope this info is useful to anyone thinking of performing a similar excercise.
Best Regards
Richard

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Re: Using Solar With BM2000 how do i reset the boiler control temp?

Post  mike on Sat Jun 23, 2012 4:48 am

Well done indeed!
And also for your very informative post.
Which no doubt will help others!
Mike
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