Back Boiler for water heating -worth it? (We have solar panels.)

selfbuildache

Hi, We're looking at getting a multi-burning stove for our new build. We already have solar panels. We were going to get a back boiler on the stove to supplement the solars (for hot water only) but the more research I do the more I'm hearing that a back-boiler is a really inefficient use of a stove, considering the panels should be heating most of the water. So, I'm thinking of getting the stove for space heating only. What do you think?
If we don't go with the back-boiler, what do people use for supplementing the solar?
Thanks as always.

ntpm

selfbuildache wrote: »

Hi, We're looking at getting a multi-burning stove for our new build. We already have solar panels. We were going to get a back boiler on the stove to supplement the solars (for hot water only) but the more research I do the more I'm hearing that a back-boiler is a really inefficient use of a stove, considering the panels should be heating most of the water. So, I'm thinking of getting the stove for space heating only. What do you think?
If we don't go with the back-boiler, what do people use for supplementing the solar?
Thanks as always.

Are you still building and in the design/construction period of the New Build.
Or has the solar and other associated heating plumbing system been completed.

Couple of questions/issues.

Have you installed the hot water cylinder yet.?
You need an open vented cylinder, a pressurised cylinder is no good.
Has the cylinder enough coils for all the heat sources i.e. 3 coiles: solid, solar and oil/gas.

The main heating source must be open vented.

You need to make provision for the stove flow/ return return pipework.
Flow has to rise all the way to the cylinder and return has to correctly run to ensure gravity flow.
Carefull consideration of location of hot press/ cylinder and height is essential.
Additional pumps and controls need to be planed,


Re back boiler or stand alone:
I would always recommend back boiler type. You get localised heating and at leasrt you are recovering some of heat that would be going up the chimney back into the heating system.
Once installed minimum maintenance required and relatively easy to use.


Re supplementing solar:
No real option other than utilising you primary heat source or the electic immersion.

L driver

ntpm,
what is your opinion of a post heater on the hot water line after the cylinder instead of the immersion?

ntpm

L driver wrote: »

ntpm,
what is your opinion of a post heater on the hot water line after the cylinder instead of the immersion?

TBO. I have no experience with installing one nor have I come across one.

I am relucant to comment too much however as they are not commonly used I would question how efficient and effective they are?

Also, I am of the opinion that if the primary heating source is configured and controlled/zoned properly for hot water only, you have (or are) outlayed a large amount of capital and labour costsalready , so why introduce additional cost with more pieces of equipment.

ADDITIONAL COMMENT:
Retro-fitting an add on heatexchanger/ heater may be more cost effective than trying to alter existing system.

selfbuildache

Are you still building and in the design/construction period of the New Build.
Or has the solar and other associated heating plumbing system been completed.

Solar and 1st fix plumbing are in.

Have you installed the hot water cylinder yet.?

Yes

You need an open vented cylinder, a pressurised cylinder is no good.

We have an expansion tank for the cylinder. Is that what you mean?

Has the cylinder enough coils for all the heat sources i.e. 3 coiles: solid, solar and oil/gas.

Yes

You need to make provision for the stove flow/ return return pipework.
Flow has to rise all the way to the cylinder and return has to correctly run to ensure gravity flow.

Done

Additional pumps and controls need to be planed.

There's a circulation pump alright and controls for the solar. Is this what you mean??

Thanks for the rest of your advice!

I'd really appreciate other (or same) opinions on this!

aquajoe

would not use it just to heat hot water....
have you rads if so i would install it