Tank thermostat fitment on solar twin coil tank?

[ferris]

I have just had a new twin coil tank fitted to my heating system for use with my new boiler and the currently fitted solar system.

the solar system was already fitted to the system when we bought the house this summer. everything was working fine, but the boiler needed replacement and system was using 2x tanks.

I have noticed the thermostat for the DHW/boiler shut off is at the bottom of the tank near the solar coil, should it not be higher on the tank?

Ferris

 

[wetshoes]

If it's the cylinder thermostat wired to the boiler/heating system then yes it's too low.

It might be the thermostat that turns the solar pump on when the panel is warmer than the bottom of the cylinder.

regards

 

[ferris]

Hi,

its the boiler thermostat, the two solar system thermostats are at the top and the bottom of the tank. so where should this thermostat be, at what level?

cheers,

Mark

 

[londonboy]

I usually fit them inbetween top and bottom of the boiler coil

 

[ferris]

thanks for that Londonboy, without looking/at a guess its currently between the in and out of the solar coil.... grrrrrr. wonder why the hot water is so bl00dy hot!

 

[Agile]

What have you gained by having a single tank fitted?

I would always prefer two seperate tanks as they are cheaper and control themselves better.

Tony

 

[ferris]

I was recomended the single tank by a few plumbers.

I had a single DHW in the old airing cup and wanted this moved to the loft to make more room.

The old solar system had its own tank and a hot-rod into the DHW tank and was told this was wrong.

so the soulution was a single twin coild tank and a new pump station instead of the old seperate pump etc. anyone here really good with Solar DHW set-ups? I am not 100% of what my plumber has done and would love a sanity check.

Ferris

 

[Agile]

The single two coil tank is the usual and most expensive solution and works well although its not necessarily the most effective as the solar storage is not that large. They are also rather over priced because the word solar comes in and thats seem as a profit boost!

I have a customer who has had someone else fit solar panels and a new cylinder for about £4000 when she does not even have any loft insulation!

I prefer a two cylinder solution as the combined storage can be larger and the cost much lower but obviously more space is required although in a loft that is not usually a problem.

Tony

 

[ferris]

maybe a future project would be to get and instal another tank for the solar system.

PS - just gone mad on insulation, but as your example there was bugger all up there in the first place (1930's house and 1980's extension). mad!

 

[ferris]

my plumber still thinks it doesnt matter where the boiler cut-off thermostat is located on my twin coil tank...

 

[londonboy]

Move it up yourself, otherwise the water will get hotter and hotter.

Cut the insulation away carefully and put this piece in the lower down hole.
Make sure its fully touching the copper!

 

[Agile]

The boiler control stat must be ABOVE the boiler heating coil.

On some the boiler coil is BELOW the pipe connections to that coil!

Tony