Thermal store cycliners - which one/any good?

[IMM]

That is probably a more cost effective route.

[IMM]

programmable

DPS do other heat banks that are either direct or indirect eliminating the need for extra plate heat exchangers, etc.

[IMM]

Another alternative. Have them with no electrics and hot water as long as you have gas and water. Well done good thinking.

[IMM]

But take it off the thermal store/heat bank. Have only the boiler heat the heat bank.

[Andy Hall]

But must be installed by an approved professional.

[IMM]

yep.

[Tim S]

Thanks IMM - I see now.

They look like they are the best designed. I like the way that most of the main pipes and pumps are presented at the front in an orderly way. Bit worried about the clever microcontroller. But I suppose, in an emergency, if it went pop, a little judicious bypassing with some wire would be possible...

But, they do seem to have thought of everything - like pump overrun and things. I had the fitter's guide off their website and it was comprehensive to say the least.

Ah - that must be what Grunff has - bit difficult searching for "range cylinders" on google :/

So far, I've seen two price lists. The Gledhill is pretty pricey, but still worth it, for all the benefits I get (not least having a useable

5x6 ft bit of space back). However, I've seen one of the others (McDonald? at around the £500-700 bracket depending on size. But after I'm finished buying pumps, controllers, random bits and bobs I'm tempted by the more expensive but nicely integrated solution.

Thanks indeed :)

Timbo

[Tim S]

I've never been a fan of unvented systems (not that I've ever had one). I just like the intrinsic safety inherent in a vented system. And remembering to do the annual safety check... No, not for me...

Timbo

[IMM]

Gledhill invented the modern version of the thermal store with a British Gas collaboration in the 1980s. They are ahead of everyone else in most respects.

Gledhill are the only company that will have a nice square box with very heavy insulation and all the controls inside the box. Their Accolade unvented cylinder is presented the same way. All the other makes look like school boiler rooms. The Potterton Powermax is all in one box, boiler and cylinder.

With a Gledhill everything is inside the box and this meas only a simple boiler may be used outside, such as a Worcester Bosch Greenstar heating boiler. Very simple and basic condensing boiler. A great advantage of heat banks/thermal stores.

[IMM]

The mains pressure is reduced. A heat bank using a plate heat exchanger may be very much higher.

[IMM]

They can be easily converted to a conventional heat bank by installing a blending valve on the DHW oulet and a flow switch on the cold mains in. A stem thermostat can be installed in the sensors cylinder pocket.

The modulated DHW pump prevents excessive mixing inside the store. Also they are twin internal cylinders. They are basically an Accolade unvented cylinder reversed. The Systemate is virtually identical

The Gledhill has the instant Switch electric backup system. This is optional. It may be cheaper to have a second cheap gas boiler to do the same job. You have to price it up. With a second gas boiler you heat the whole house as well as the DHW.

[timegoesby]

On searching the web on thermal stores, I came across this. "For new house builders to get planning permission for your home from the local authority, your hot water has to be drinkable (Potable). Hot water can no longer be tank feed from lofts for new homes as it's inefficient and not healthy."

This was taken fropm this site.

this true? If this is true cold water tank systems are outlawed on new houses and extensions.

[Tim]

Yeah - I came across that...

I've never heard of this before and would be inclined to think that they're talking b*ll*cks to get you to buy their systems.

Always be wary of quotes about the law etc. made by a vendor...

Timbo

[W]

Why? I was thinking of getting one of these (Albion mainsflow) because of their simplicity.

W

[W]

??? According to the price lists that I have seen Albion is the cheapest.

W

[IMM]

Prices must have changed.

[Christian McArdle]

Advantages:

1. Simplicity.
2. No electrical power.

Disadvantages:

1. Reduced pressure (may not matter, depending on your supply).
2. Water temperature variable with flow (can be fixed with external TMV).
3. Lower maximum flow rate before temp drops too low.
4. Internal heat exchanger makes descaling difficult and replacement impossible.
5. Worse destratification compared to external loop, leads to more gradual temp drop over long draw off, rather than remaining hot until sharper cut off.

Christian.

[IMM]

What price list?

[IMM]

Internal coils are not as efficient as a plate heat exchanger with plates delivering higher flow rates. Coils are a pig to descale, while a plate can be just screwed off and de-scaled as a DIY job. Replacing then plate is an equally simple job. The only thing extra using a plate is a normal CH pump, available locally everywhere, and a flow switch. Not much extra complexity. You can also add extra plates for a higher flowrates, try doing that with an internal coil.

[IMM]

Also try:

square thermal stores.