Mini Store - Heat Geek / Newark Cylinders for ASHP

[Beelbeebub]

56 minutes ago, dpmiller said:

 

not everywhere. Mains gas is still quite a new thing in NI and going from a vented tank/ oil boiler/ Willis combo is a steep learning curve for many...

To be fair,.we.had some tenant who moved from a coal fire in each room and immersion to a combi and they struggled with how little they had to do. 

 

At one point they were having issues and it turned out they were leaving it off and turning it on each time they wanted hot water! They complained it was too inconvenient to walk from the bathroom to kitchen to turn the boiler on to wash their hands! 😁 It took a while to impress upon them that they just needed to leave it on and not touch it at all. 

 

 

[JamesPa]

2 hours ago, Beelbeebub said:

For better or worse, the combi is the yardstick. 

 

I don't think people really need actually infinite hot water. They just want to not have to think about it. 

 

They also want the space a big cylinder takes up for other things. 

 

Right now the relatively big cylinder specified by manufacturers and installers is a bit of a barrier. Both in cost and size. 

 

The HG system is a good attempt at making the installation a bit lower friction. 

 

As long as the hot water delivery is good enough - ie the times where the customer has a tepid shower or has to wait 20mins for the cylinder to recharge are very few, then it's a great idea. 

 

A 9kw instantaneous water heater (variable power controlled to just top up the temp if too low) afterwards would extend the hot water delivery time and not fall foul of g3 regs. 

And I think that's the point.  In many cases it's good enough.  Nobody is claiming it's a universal solution and I think we have established that there isn't and won't be one.  

[JamesPa]

54 minutes ago, Beelbeebub said:

To be fair,.we.had some tenant who moved from a coal fire in each room and immersion to a combi and they struggled with how little they had to do. 

 

At one point they were having issues and it turned out they were leaving it off and turning it on each time they wanted hot water! They complained it was too inconvenient to walk from the bathroom to kitchen to turn the boiler on to wash their hands! 😁 It took a while to impress upon them that they just needed to leave it on and not touch it at all. 

 

 

That's hilarious.  Perhaps you need to fit placebo controls

[SimC]

I would be interested for thoughts on using one of these to convert from a vented hot water cylinder fed by a system boiler via a 3-port diverter valve to a hot water system under mains water pressure.

 

Presumably it avoids the full G3 requirements as the hot water coil must contain less than 15 litres volume within the pressurised circuit from non-return valve to closed hot water taps. Does the G3 requirement for a pressure/temperature relief valve and associated drainage then go away?

 

I already run the boiler at around 50C flow temp for heating, then turn up to around 70C on 1 day per week to heat the full tank for bath day. The remaining 6 days use an Eddi plus immersion for night/solar hot water heating of just the top half of the tank which is sufficent for showers and washing up. Presumably with the MiniStore the boiler flow temp would not need to be so high, and the 15 kW boiler would be able to provide enough top up to be able to fill a bath. The current hot water cylinder is approx 1100 H x 475 D, the same as the Tall MiniStore.

 

Just trying to think outside the box with immersion backup possible by using a Willis heater connected between the heat source flow and return connections to the MiniStore. The existing boiler system is already vented with expansion up to the loft header tank.

[JohnMo]

8 hours ago, SimC said:

I would be interested for thoughts on using one of these to convert from a vented hot water cylinder fed by a system boiler via a 3-port diverter valve to a hot water system under mains water pressure.

 

Presumably it avoids the full G3 requirements as the hot water coil must contain less than 15 litres volume within the pressurised circuit from non-return valve to closed hot water taps. Does the G3 requirement for a pressure/temperature relief valve and associated drainage then go away?

 

I already run the boiler at around 50C flow temp for heating, then turn up to around 70C on 1 day per week to heat the full tank for bath day. The remaining 6 days use an Eddi plus immersion for night/solar hot water heating of just the top half of the tank which is sufficent for showers and washing up. Presumably with the MiniStore the boiler flow temp would not need to be so high, and the 15 kW boiler would be able to provide enough top up to be able to fill a bath. The current hot water cylinder is approx 1100 H x 475 D, the same as the Tall MiniStore.

 

Just trying to think outside the box with immersion backup possible by using a Willis heater connected between the heat source flow and return connections to the MiniStore. The existing boiler system is already vented with expansion up to the loft header tank.

No G3 requirements for these cylinders.

 

But if you have room for a cylinder use a cylinder. If there is an issue doing the drain side of things for an unvented cylinder, look at a harlequin cylinder, they also require no G3. Or go full UVC but specify a heat pump cylinder, store at lower temperature your boiler will condense throughout the full heating cycle due to the big coil.