DPS thermal store DHW performance

Ah, useful information - didn't know about the modulating controller,

The Gledhill pcb has labeled screw terminals on it and connections for a time clock...and even room stat terminals to switch in the boiler/CH pump. It can be easily fitted in a vented metal box. A Google says the pcb's are £240 inc VAT plus sensors at approx £28. You need the modulating Grundfos pump, not a normal off the shelf job.

No flow switch or TMV is needed, or the two cylinder stats and relay, saving money there to offset costs. No need to set up the stats and the pcb does all.

You may as well use the Gledhill pcb as most, if not all the functionality you need the pcb offers. Heat the cylinder switching in the boiler, using one sensor in a pocket. It has three temperature sensors. One sensing the cylinder temp, one sensing the plate temp in the pipe after the plate on the primary side, one sensing the DHW temp just after the plate in the pipe.

It has the built-in anti-cycle functionality that two cylinder stats gives. Once up to temperature the boiler does not cut in until the thermal store temperature drops substantially. Below 60C cylinder temperature the CH pump will be held off to give a swift reheat of the cylinder, if you wire in the CH part. All quite simple. The pcb "learns" the boilers maximum temperature and heat up time. It will run from 70C minimum to 80C learning the boilers ways.

Using the Gledhill PCB is the cheapest way when building a custom store with rich functionality and economy. All parts are there readily available and cheap enough, and simple to implement. One pcb, three temp sensors and a modulating Gundfoss pump. All simple and all done for you. Just connect up. It even gives temperatures of the sensors on a display on the pcb.

Gledhill should have made stainless versions of their thermal stores with PHX's inside the cylinder with the CH taken off an internal coil to prevent sludge build up. Then they would have sold like widfire and given few problems improving the reputation of thermal storage. Gledhill had the right idea of all in one highly insulated neat box, but the mechanical design and/or materials left a lot to be desired in some points. The pcb was/is superb with superb functionality simplifying some of the mechanical aspects and improving efficiency.

Because of the Credit Crunch Gledhill have "temporarily" dropped the advanced thermal stores, reverting to coiled DHW stores. All parts are available for all previous models. The pcb was made in Czechoslovakia for Gledhill. There is no reason why Gledhill cannot sell these pcbs to other thermal store makers, unless they seriously intended to resume manufacture of the older products, or have a newer product on line using the same pcb.

Other makers using this pcb would make thermal stores much more efficient and cheaper all around. Then thermal store pcbs would be generic and interchangeable.

The maker. A quality company..
http://www.elok.cz/en/products/electronics#34

It may now be a general pcb available to any makers. This is the pcb used by Gledhill, from the Czech web site and appears to be generally available to other makers....
gt155.jpg


The Czechs have two pcbs on their catalog. The pcb shown above....

The unit is designed for controlling thermal stores. It controls the temperature of the water in the store and the preparation of domestic hot water. The unit can be expanded in order to control thermal systems with condensing boilers, solar panels. Also the unit can transmit data by means of GSM.
 
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The heat loss is big enough. It also gives great packaging, which is needed in domestic appliances. The PHX, and associated DHW pipework (this can be 28mm inside to give a larger volume of preheated DHW) inside the cylinder, is also preheated. With a DHW PHX and pump "inside" a cylinder a check valve is not needed. Heat loss from the pump is captured inside the cylinder. Having the CH pump inside also captures wasted pump heat

Understand what is being put across, as all I am doing is repeating myself to you.

Thermal storage and thermal systems in general are vastly misunderstood by the average plumber.

CH Pump inside what
 
A CH pump in the cool bottom section of the cylinder. It will remain cool with a more even temperature over the pump. Heat from the pump is captured. Immersed pumps are common. There is no reason why they cannot be immersed in heating and water systems.
 
There is no technical info on this cylinder, just the blurb on the web site, I am not aware of CH pumps been immersed in the vessel water, never heard of it, sounds total nonsense to me, you are just taking what is on their web site, have you ever fitted one, what make of pump do they use internally, I have given the web address of the store to a German collegue of mine, first thing he said is "why is it impossible to get good technical information from an English web site" it is lacking in full technical details of this store, I would want to see far more technical info than what they have here http://www.nu-heat.co.uk/s.nl/it.I/id.706/.f its just all sales blurb
 
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There is no technical info on this cylinder, just the blurb on the web site,

Enough info is there. It is a pressurized cylinder charged to 1 bar with a 3 bar blow-off valve. A separate expansion vessel will need to be fitted.

I am not aware of CH pumps been immersed in the vessel water, never heard of it, sounds total nonsense to me,

You are obviously a hands on fitter. Engineers know about immersed pumps. They even have them in fish tanks ....and solar applications. The point was that there is no reason why immersed pumps cannot be fitted... and should be fitted. Engineers think ahead and aim to improve. Fitters only know what they know. ;)

Your German mate should know the obvious, that an immersed plate does not lose heat. ;)
 
immersed pumps may be fitted in fish ponds etc, but these are low voltage pumps all pumps can fail, so how would you go about changing one of these pumps at the bottom of a cylinder, the blurb on the site is not what I call technical, its sales led, you are singing the praises of this store without ever fitting one, personally I will never promote anything unless I have fitted one, you cannot promote a product based on the sales litreature from the manufacturer, I will wait until I have either the chance to see one in action or fit one before I would big it up
 
Amazing the views on pcb reliability..
This says..

//www.diynot.com/forums/viewtopic.php?p=1590588#1590588

I have fixed quite a few for Gledhill locally and can say that the pcb is the worst one I have ever come across.

While this says.....
//www.diynot.com/forums/viewtopic.php?p=508521#508521

It would be much simpler to fix the Pulsacoil rather than decommission it. And I've maintained heaps of these things without once seeing a faulty PCB.

Amazing. I am not aware of Gledhill having poor quality pcbs - from a maker that does industrial pcb control?
 
immersed pumps may be fitted in fish ponds etc, but these are low voltage pumps all pumps can fail, so how would you go about changing one of these pumps at the bottom of a cylinder,

From a lid at the top and lift it out or an low level access panel.

the blurb on the site is not what I call technical, its sales led,

What issue do you have with the thermal store? Apart from not figuring out that heat loss is NIL, what issues do you have?

You are a fitter - you fit what others design. Leave the thinking to engineers. Do not get above your station, as it clearly shows and you may seriously embarrass yourself....as you are now. In real life amongst engineers, just keep quiet. ;)
 
From a lid at the top and lift it out or an low level access panel.
Hmmmmm, the top is full of hot water, the lower access panel holds back 100+l of hot water. That's going to be nice and convenient for working in.

A thread I started on another forum is here - that link takes you to the later incarnation of my musings. Of course, after your earlier tip, I can see that a suitable valve & sensor option is available with a Danfoss 3 port valve and remote sensing head.

I find the Gledhill controller board interesting too. I think I'm going to be going though a few ideas before I get round to my next project :rolleyes:
 
immersed pumps may be fitted in fish ponds etc, but these are low voltage pumps all pumps can fail, so how would you go about changing one of these pumps at the bottom of a cylinder,

From a lid at the top and lift it out or an low level access panel.

the blurb on the site is not what I call technical, its sales led,

What issue do you have with the thermal store? Apart from not figuring out that heat loss is NIL, what issues do you have?

You are a fitter - you fit what others design. Leave the thinking to engineers. Do not get above your station, as it clearly shows and you may seriously embarrass yourself....as you are now. In real life amongst engineers, just keep quiet. ;)

I have no issues with thermal stores, I have fitted hundreds, but you are trying to rate a unit that you have never fitted, you are only relying on the sales stuff from the web site, just like a Google Warrior, this is a plumbing forum, not an engineers forum, although I doubt very much that you are an engineer, more than likely a Google warrior, probably, Dr Drivelb re-incarnated and we know he is neither an installer or an engineer.
A pump at the bottom of a store where you have to remove a lid to gain access to the pump, then have to remove it from the store, what a load of tosh, if one did exist it would not sell very well, who on earth would want to deal with that for a pump change, I see nothing on the site to suggest that the Nu-heat store has a submersed pump, please show me the details of a store wiith a pump that is in the body of water, I would be intersted in seeing this, I doubt you will find one cos I know you are talking ****
 
From a lid at the top and lift it out or an low level access panel.
Hmmmmm, the top is full of hot water, the lower access panel holds back 100+l of hot water. That's going to be nice and convenient for working in.

Simon, You work on it cold. A lift off lid is very easy to work on, as is an access lid when drained down. Makers haven't cottoned onto this immersed pump yet.

I looked at the Navitron site - complicated. The Gledhill (Czech Elok) pcb board is by far the cheaper option. A Danfoss remote sensor valve and actuator head is more expensive than the Gledhill pcb. The pcb also offers excellent functionality and promotes economy in maintaing stratification. Download a Boilermate 2000 or Systemate 2000 instruction manual (the same pcb). It tells you the functionality of the pcb. The pcb can do all basic functions of DHW and boiler control, depending on what you want to do of course.

You may want to link this thread from the Navitron forum, regarding the Czech pcb. Warn them that a goon has infiltrated the thread. I think it is a generic pcb and not specific to Gledhill, as it is on their product list.

The pcb can switch a boiler pump and CH pump. It is best to have the board energize a small cheap relay and the relay switch the pump. Seized pumps tended to burn out the pcb when wired directly, although I "think" that problem has been rectified now on the pcb. The pump's current went through the pcb, using a relay removes the heavy current from the pcb. The DHW has to go through the pcb with the pump set to max speed as the pcb modulates it.

The pcb spins the CH pump every 24 hours to prevent seizing, that is if you have separate CH pump. The pcb calls in the boiler pump and boiler separately. If you have a system boiler with an integrated pump, then only the boiler need be called. You can have the boiler with its own permanent live and only use the switched live from the pcb. The store need only be set to 72C.

The pcb also uses the DHW pump as a shunt pump to get the store an even temp all the way down, packing in more stored heat enabling a smaller cylinder if the need be, or longer spells between heat calls from the boiler (eliminates cycling). From memory, the shunting is towards the end of the store heat up. Once up to temp all down the cylinder the boiler is not brought in until the store drops a certain temp to prevent boiler cycling (the same function as two cyl' stats using one temp sensor). Stratification takes hold with thermal layering. The thermal layering is not upset as the pump modulates.

If you are building a custom thermal store I suggest you use the Gedhill pcb and the three sensors. Cheap and gives you what you want in maintaining stratification....and even more. Also have the boiler heat the store directly.

Systemate manual with large drawings of the pcb.
http://www.gledhill-spares.net/documents/SysteMate2000-Iss10.pdf
 
I have no issues with thermal stores, I have fitted hundreds,

OK you have fitted thermal stores. Fantastic. Designing one is not in your capability, nor is understanding some of the basics of thermals. Most who fit combis haven't a clue how they work either. Stop digging yourself into a deeper ditch and making yourself look even more foolish. You revert to the internet ploy of when proven wrong revert to personal insults. It is best if you wrote, "thanks, I never knew that". You can't even get simple points or read properly - probably a low attention span. I got a similar response from a goon on the electrics forum then he ended up being castigated by others on the thread.
:(

Now run along. :)
 
Guys

The discussion topic is interesting. I'm neither a fitter or designer, I am an interested owner. I spent a lot of time researching the product and am in general happy with its performance.

Since returning home, I have turned up the boiler stat to Max, this has resulted in the production of a greater volume of available water, that is continously available - bath after bath.

My own conclusion is that with the boiler turned down it had to fire for longer to get the TS up to it's stat temperature (70). Then after DHW was used it couldn't generate enough heat to reheat the store quickly to prevent DHW running out.

I'll continue to monitor this over the next few days and report back.

I may also investigate the possibility of the boiler side PHX being slightly scaled/blocked as earlier suggested.

Any further input is appreciated.
 

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