Gledhill Boilermate 2000 & The ever increasing cost of gas/electricity

RedFraggle

BUFF said:

RonRamsgate said:

Anyway due to having 2 baths,2 showers with body jets which were often in simultaneous use and many other hot water outlets we opted for an unvented cylinder as a combi would not supply sufficient water flow.
Our installer mentioned high output gas combination gas boilers but they said they are expensive to heat up hot water and there will still be hot water flow restrictions.
Since fitting the unvented cylinder our gas consumption reduced 35%  No constant boiler cycling on/off. No noise from the three grundfoss pumps.

Yes, for 2 bathrooms & 2 showers with body jets you are going to need stored dhw. Even the largest storage combi wouldn't cope with that simultaneous demand. iirc a WB 550CDi is 25l/min.

Did you upgrade the boiler at the same time or do you still have the Suprima? 

I thought an unvented cylinder was still a thermal store and not stored hot water. 

Bendy_House

I 'think' the essential difference betwixt an unvented and a thermal store, is that the former is 'just' a mains-pressurised hot cylinder, so delivers copious amounts of DHW to more than one tap, and the TS does more. It holds water at a higher temp, and then uses this water to supply the CH. It also instantly heats DHW via a coiled copper pipe (a heat exchanger) inside it.

I would ONLY have a TS if there were other heat sources such as solar, PV, ASHPs, stove back boiler, etc.

BUFF

RedFraggle said:

BUFF said:

RonRamsgate said:

Anyway due to having 2 baths,2 showers with body jets which were often in simultaneous use and many other hot water outlets we opted for an unvented cylinder as a combi would not supply sufficient water flow.
Our installer mentioned high output gas combination gas boilers but they said they are expensive to heat up hot water and there will still be hot water flow restrictions.
Since fitting the unvented cylinder our gas consumption reduced 35%  No constant boiler cycling on/off. No noise from the three grundfoss pumps.

Yes, for 2 bathrooms & 2 showers with body jets you are going to need stored dhw. Even the largest storage combi wouldn't cope with that simultaneous demand. iirc a WB 550CDi is 25l/min.

Did you upgrade the boiler at the same time or do you still have the Suprima? 

I thought an unvented cylinder was still a thermal store and not stored hot water. 

https://www.easyflow.co.uk/articles/unvented-cylinders-vs-thermal-store-water-heaters-how-your-options-stack-up
https://www.gondwanagreenheat.co.uk/thermal-store-versus-a-hot-water-cylinder/

A thermal store is still stored hot water (I probably shouldn't have put in the "d" & left it at stored hot water) .

RedFraggle

BUFF said:

RedFraggle said:

BUFF said:

RonRamsgate said:

Anyway due to having 2 baths,2 showers with body jets which were often in simultaneous use and many other hot water outlets we opted for an unvented cylinder as a combi would not supply sufficient water flow.
Our installer mentioned high output gas combination gas boilers but they said they are expensive to heat up hot water and there will still be hot water flow restrictions.
Since fitting the unvented cylinder our gas consumption reduced 35%  No constant boiler cycling on/off. No noise from the three grundfoss pumps.

Yes, for 2 bathrooms & 2 showers with body jets you are going to need stored dhw. Even the largest storage combi wouldn't cope with that simultaneous demand. iirc a WB 550CDi is 25l/min.

Did you upgrade the boiler at the same time or do you still have the Suprima? 

I thought an unvented cylinder was still a thermal store and not stored hot water. 

https://www.easyflow.co.uk/articles/unvented-cylinders-vs-thermal-store-water-heaters-how-your-options-stack-up
https://www.gondwanagreenheat.co.uk/thermal-store-versus-a-hot-water-cylinder/

A thermal store is still stored hot water (I probably shouldn't have put in the "d" & left it at stored hot water) .

Thanks BUFF

RedFraggle

Bendy_House said:

I 'think' the essential difference betwixt an unvented and a thermal store, is that the former is 'just' a mains-pressurised hot cylinder, so delivers copious amounts of DHW to more than one tap, and the TS does more. It holds water at a higher temp, and then uses this water to supply the CH. It also instantly heats DHW via a coiled copper pipe (a heat exchanger) inside it.

I would ONLY have a TS if there were other heat sources such as solar, PV, ASHPs, stove back boiler, etc.

Yeah. thanks Bendy House. I'm familiar with them, was just confused by the post. Have lived with a gledhill boiler mate system (pros and cons) and currently purchasing an electric only flat with a gledhill puracoil thermal store on e7

akm17

Hello, anyone with BM2000 tempted to cover the storage water box with extra PIR or similar insulation? I can understand the benefit of BM2000 system over combi, especially really good shower temperature and pressure (encouraging short shower), but feels like so many heat losses (although it is in the middle of the house, so it is heating up the usable space).