New PV solar install arranged, heating upgrade advice please - solar compatible hot water tank

NoobSolar

I have the Gledhill stainless cylinder with two immersions and an iboost. I don't find problems with it so I don't think I would need a destrat pump.

mickyduck55

NoobSolar said:

I have the Gledhill stainless cylinder with two immersions and an iboost. I don't find problems with it so I don't think I would need a destrat pump.

Totally understand but re the original question "I think" you would only need one immersion if you had a destratification pump.
That would remove any issues with having to have two immersions driven by the iBoost.  Does it split the diversion between the two immersions equally? 

Just read the manual it suggest powering the bottom immersion so that indicates the simplest solution is just have one immersion in the bottom of the tank

ispookie666

Recirculation pump or destratification pump is a good idea. 
Can this be retrofitted? 

paul991

i dont see the use of a destat pump for a domestic tank. a  recirc pump would  be good if you live in avery  large house to give  hot water with little  wait time

mickyduck55

paul991 said:

i dont see the use of a destat pump for a domestic tank. a  recirc pump would  be good if you live in avery  large house to give  hot water with little  wait time

With a standard size top mounted immersion the bottom of the tank is usually cooler than the top.  As the thermostat is also in the immersion heater the solar diverter (and mains electricity) is turned off before the complete tank is at the set temperature.
Solutions (I think) as Destratification  pump or longer immersion element.

Personally I have not bothered but if a retro fit pump was an option without changing my tank I would probably go for it.

paul991

yes  on my standard  tank that is the case its never been a problem with only the darkest  days not  having enough hot water but in a commercial setting would be worthwhile as would be using much larger tank its best to feed second output to a electric radiator or convector  heater,usually a long  immersion element is mounted at the  top and  short one at  bottom  

QrizB

ispookie666 said:

Recirculation pump or destratification pump is a good idea. Can this be retrofitted? 

and

mickyduck55 said:

Personally I have not bothered but if a retro fit pump was an option without changing my tank I would probably go for it.

In principle, if you've got suitable tappings at the top and bottom of your tank (or if you want to fit a pair of shower flanges) it shouldn't be too hard to retrofit a pump.

https://www.youtube.com/watch?v=n3RbIkQJ11I

Reed_Richards

I have a recirculation pump for my hot water but the return feeds in towards the top of the tank so it does not destratify.  A quick lock online suggest that pumps suitable for potable water cost upwards of £125 so a destratification pump is not a cheap option.

I looked at using my recirculation pump for destratification but that would require at least one motorised valve and motorised valves suitable for potable water are both hard to find and expensive.   

mickyduck55

@QrizB
thanks for the video.. I don't think so LOL

I'm a reasonable DIY plumber but that is a lot of messing about for not a lot of gain.  I did installed a Surrey flange on the top when I installed the shower.

Re the video..
1.I would have a MUCH longer safety wire probably longer than the height of the tank so no chance of dropping it inside 
2. If he thinks that is working in a confined space I really have no idea how he would describe doing that in an airing cupboard which is what most of us would be dealing with

I wonder if running some water off to force a cold refill would stir it up a bit or maybe run the gas heating through the coil would destrat to a degree.. now I am clutching at straws

Solarchaser

For recommendations I'd go with this
https://www.advanceappliances.co.uk/product/153-electric-thermal-store-hot-water-only/

@Coastalwatch has one, I'm planning on buying in in the next month or so.
Thermal store means the water is clean as its only heated when run through the coil.

I will be ditching my gas and going electric as I've wanted to for a while, and when gas is 7.5p and electric on the cheaper rate is 7p then its cheaper to heat by electric.

The problem is the cheap rate is only 3 hours for me, so an electric boiler to heat a large water tank, or internal immersion heaters is the way I'm going.