How to setup a DPS GXV or Pandora heat store system

[speedyuk]

Hello folks,
I'm not a plumber but will be getting someone in to do this for me and would like to know what's involved before I start.

I want to install a DPS GXV 250l heat bank. It will be located in the cellar. The expansion tank will be in the loft (8m above). There will be approx 15 radiators totalling 45,000 BTU. 2 bathrooms. 5 people in the house so estimate a requirement for 24KW condensing non system boiler, but will fit a 30KW instead. This will heat the store water directly. The boiler will be in the kitchen on the ground floor. The DHW and CH will be from the heat bank.

I want to have underfloor heating in the kitchen and bathroom (x2) and someone has suggested that if the area is not too big, I can have a CH spur so in effect treat it like a radiator as well for each area.

I also want be able to have the ability to fit solar panels if I want (maybe in the future). Should I have the solar panel kit fitted on the heat bank from now?

I am estimating heat bank to cost approx £1300. Boiler perhaps a WB/Vaillant to be around £700.

Does all this sound realistic? I've read that it's important to have specific components setup correctly, such as automatic valves, TMV, dual thermostat etc. Could someone be kind enough to explain how this would be setup in layman terms and what I should ensure that the plumber should do (since they may not have setup a similar system).

I'm also having all the pipes replaced since it's a house renovation and the old pipes are quite old. Is the person who does all this generally corgi registered or not? How much do you think the labour charge for installing boiler heat bank, rads and pipes should cost assuming nothing too complicated (I know people will roll their eyes at the how long is a piece of string type question)

A lot of questions, but hopefully people will be able to answer bits of it if not all.

Appreciate your help

 

[croydoncorgi]

CORGI (traditionally) applies only to gas.
But CORGI also operates 'competent persons' schemes for plumbers and (even) for electricians.
What I think of CORGI wasting MY money on its own money-making schemes and other related issues would fill volumes - but I digress.

If you want a 'professional' to fit what you describe (a relatively complex system involving a heatstore AND solar panels) you'd be well advised to find someone who's done at least a few before. You'd also be well advised NOT to start out second-guessing what he proposes to you! Guaranteed to upset your relationship.

What you should do is write down what you want done (you seem to have researched it already) and invite estimates from a number of heating engineers (NOT just 'installers'). Then use your skill and judgement to select a supplier, agree terms and deadlines, and let them get on with it.

 

[nickso]

a pandora cant be £1300 is it?

i was considering one of these for install in the summer but i wont be at that price.

 

[Agile]

If you have calculated the heat requirement at 24 kW then why do you want to fit a more powerful boiler? That just makes it more inefficient.

You say the rads are 45,000 BTU. I only think in kW but that must be about 13.5 kW. The energy efficiency sizing is to add just 2 kW for hot water demand.

That means an 18 kW boiler would be more than adequate! A Worcester 18Ri would be a good choice!

Oversizing makes it inefficient !!! It cannot modulate down far enough!

Tony

 

[speedyuk]

nickso : £1300 (inc VAT) is for the more larger store (250l). I think most heat stores around that capacity are not cheap. I wouldn't be thinking of installing it except I'm having major renovations done... I'm hoping I can get the price reduced, fingers crossed.

Agile : The reasoning used was 13.5KW for heating and 2KW per person (x5) coming to 24KW. The extra was to ensure more quicker heating of the store. Perhaps, like you said, I am over estimating. If an 18KW works, I'm happy. So, should it be 2KW DHW in total and not 10KW as I had guestimated?