Linking oil boilers to solar Pv panels

[Pebroo]

Hi all.
I am thinking about how to get the most from pv panels. I have a worcester Green star oil Combi boiler about 5 years old.
If I install a mains pressure immersion tank can I convert the boiler to a non combi type? And heat the water in the tank with the boiler.
Also is it possible to pre-heat the water in the heating system using a second mains pressure tank? I have underfloor heating so the running temperature is relatively low.
I hope this makes sense feel free to call me bonkers.
Thanks

 

[SJB060685]

To your first questions.
Yes its possible to install a mains pressure cylinder and have the boiler heat it. There will obviously be substantial alterations installing the new cylinder and adjusting pipework to suit, a long with some additional cable routing and wiring up.
What you're proposing is common on combi systems and usually the engineer will leave one hot water outlet connected to the combi boiler, usually this would be the kitchen sink, although could be any depending on location of boiler and closest outlet.
The second part im not sure im with you.
Are you saying you have solar thermal or PV?

 

[snowhead]

You need to do some accurate calculations to prove there's a return on the cost of the work.

Unless you're doing it solely for being Green purposes.

 

[Pebroo]

To your first questions.
Yes its possible to install a mains pressure cylinder and have the boiler heat it. There will obviously be substantial alterations installing the new cylinder and adjusting pipework to suit, a long with some additional cable routing and wiring up.
What you're proposing is common on combi systems and usually the engineer will leave one hot water outlet connected to the combi boiler, usually this would be the kitchen sink, although could be any depending on location of boiler and closest outlet.
The second part im not sure im with you.
Are you saying you have solar thermal or PV?

It pv I’m installing
how about this? A mains pressure tank heated by pv panels feeding hot water to the Combi boiler and the boiler only heating that water if necessery? So instead of cold water going into the boiler hot water will go in and the boiler will only heat it if the temperature is lower than the stat is set at.
And another mains pressure tank heated from the pv panels incorporated into the pressurised sealed heating system so that the load is reduced from the boiler? Ive got a feeling if I put these ideas to an engineer on site he would walk away

 

[SJB060685]

PV generates electricity, solar thermal preheats water. Dont get confused between the two.
Some combis allow the hot water for taps to be preheated through a storage cylinder yes but certain criteria needs to be met, so I would check with worcester first and if so needs to be installed correctly.
Your second idea would need a thermal store. The solar thermal would do the majority of the heating and the boiler just tops up in times of low UV.
Again careful design and installation is needed.

 

[SimonG]

Combi boiler feeds kitchen hot tap. PV heats unvented cylinder for other outlets and feed off of combi to top up hot water when required.