Gledhill Thermal Store - I thought it was economical!

[BigBurner]

However if you ran the store on a timer you could have a 20 - 30 minute wait for hot water.

Not so in a Boilermate 2000. Thermal layering ensures that hot water is available within minutes. The boiler heats the cylinder top down, unlike a coiled cylinder which is top up. This ensures that useful hot water is at the top of the cylinder within minutes. The DHW plate heat X takes this hot water from the top and uses that. As the pump modulates it only takes what it need from the top of the cylinder.

Put it this way. If a 28kW boiler is coupled to a Boilermate 2000. The store is cold. You switch on the store. Go into the bathroom, undress and turn on the shower. By the time you have done this enough hot water will be at the top of the cylinder. Then the shower will be drawing hot water off and the boiler heating the top of the cylinder an the same time. This is "instant" hot water like an infinitely continuous combi.

I know there are timed versions but the basic principle of the thermal store is theat it constantly sits around 62 deg.

That is not the basic principle at all. You can time it to go off overnight and have it at running temperature during the on period.

The principle of a BoilerMate 2000 is to separate the heat generator, e.g. a boiler, from heat emitters (radiators) by a buffer (thermal store). This evens out the fluctuating demands for heating and hot water. By storing energy produced when the demand is low and discharging it when the demand is high, i.e. during property warm up or when hot water is drawn off, a smaller boiler can be used.

An important aspect of this concept is that hot water can be supplied directly from the mains at conventional flow rates without the need for temperature and pressure relief safety valves or expansion vessels. This is achieved by passing the mains water through a plate heat X. The outlet temperature of the DHW is maintained by a pcb board, which controls the speed of the pump circulating the primary water from the store through the plate heat exchanger.

A thermal store does not care how big the boiler is when it is couped "directly". The boiler will dump all its heat into the store giving a very fast reheat. 28mm flow and return pipes can handle approx a 70 kW boiler. A 50 to 60 kW boiler coupled to a Boilermate 2000 will supply three bathrooms providing the water flow and pressure is adequate. When a 50kW boiler is reheating the store it is the equivallent of approx 22 litres per min. The boiler and stored energy combine to give high extended outputs.

 

[gas4you]

DD is back again

 

[BigBurner]

DD is back again

He must be a hell of a fella. So in demand.

 

[ollski]

Seems to have develpoed into a post about a specific unit rather than thermal stores in general which I was initially referring to.
In my area we tend to have standard boilermates (i think!) and gulfstreams which are all 24/7 on the store. The only way to stop the boiler firing to heat the store is to isolate the mains power.

 

[Norcon]

Ollski wrote

The only way to stop the boiler firing to heat the store is to isolate the mains power.

You can fit a two channel timeclock to control the boiler firing. It explains this in the MI's.

 

[BigBurner]

Seems to have develpoed into a post about a specific unit rather than thermal stores in general which I was initially referring to.
In my area we tend to have standard boilermates (i think!) and gulfstreams which are all 24/7 on the store. The only way to stop the boiler firing to heat the store is to isolate the mains power.

All Gledhills can have a normal 2 channel pogrammer fitted. The terminals are in the installation manual and clearly marked on the pcb. The standard from the factory has the DHW linked out.

It is a simple matter of removing the wires from the integral CH clock and connecting a normal remote CH & DHW programmer.

One option is to wire the integral clock for DHW only and have the CH linked out to operate 24/7. Then use a programmer stat.

Gledhills are so well insulated that they say it is not worth turning it off. The pcb will heat the store from 76 to 82C and then only reheat when the store is below 60C. The store will stay above 60C for many, many days. In reality you will need to turn on the DHW on 30 minutes before the CH is to be switched on, to give enough hot water to pump around the rads. The rads are heated instantly

 

[Prabha]

Thanks for all the replies and possible technical causes for the way thermal stores work.

I have two stores, one for central heating which runs on clock. There is no problem with heating during winter.
The other store is for hotwater, on 24/7 without any clock control.
It has a separate electric immersion heater, which also does not have a clock control. It is not the one you can switch on the front. The switch is ordinary switched plug connection outside the store. It is only the hotwater system that is running the boiler, even when no hat water is being used - either during the day or at night.
The thermal store is in a very insulated room with no draughts or other obvioius cause for heat loss. Is it possible to run the immersion heater only during summer - as the demand for hot water is very little (we take showers) and there are only two of us now that the children have all left the nest. What would happen if I switch of the boiler, and run the immersion heater only during summer?

Prabha

 

[Norcon]

Prabha wrote

I have two stores

Thought you said you have a boilermate 2000 ?.
If you have a second store what is the make ?.

 

[Prabha]

Both are boilermate 2000s - one exclusively for underfloor heating on one floor, the other for ordinary radiators and all hot water. All radiators have individual thermostat controls with an overall master thermostat in the landing.

Prabha

 

[Norcon]

Both are boilermate 2000s - one exclusively for underfloor heating on one floor, the other for ordinary radiators and all hot water. All radiators have individual thermostat controls with an overall master thermostat in the landing.

Prabha

Is this a wind up ?. Every time you post you contradict your previous post.
As explained by Bigburner its very easy to control the firing of the boiler.

 

[Softus]

Thanks for all the replies and possible technical causes for the way thermal stores work.

You might as well consider this topic to be yours, since the OP has never come back.

I have two stores, one for central heating which runs on clock. There is no problem with heating during winter.
The other store is for hotwater, on 24/7 without any clock control.

Frankly, I don't believe you.

Do you also have two boilers?

It has a separate electric immersion heater, which also does not have a clock control. It is not the one you can switch on the front. The switch is ordinary switched plug connection outside the store.

Are you sure that this isn't a Pulsacoil 2000?

It is only the hotwater system that is running the boiler, even when no hat water is being used - either during the day or at night.

Are you saying that your Boilermate 2000 has immersion heaters AND is connected to a gas boiler?

The thermal store is in a very insulated room with no draughts or other obvioius cause for heat loss.

Please stop referring to things as thermal stores - use only the make and model of the thing that you're talking about.

Is it possible to run the immersion heater only during summer - as the demand for hot water is very little (we take showers) and there are only two of us now that the children have all left the nest. What would happen if I switch of the boiler, and run the immersion heater only during summer?

It isn't possible to answer that yet, on account of you having a system that you can't describe.

Which boiler do you have, and where is it?

Which Gledhill appliance do you have, and where is it?

Which other Gledhill appliance do you have, and where is it?

What are the symptoms of the fault that you believe you have?

 

[Prabha]

Thanks again for all your replies. Most of you must have gathered that I am not in the trade. The idea is not to DIY and that is why I came to this site.

Bigburner seems to understand the problem and his suggestion sounds plausible.

I will get one of the local Gledhill certified installers to come and look at it.

Please do not post any further replies to this account.

Thanks again for all responders.

Prabha