Excessive Solar Panel Heat

mickburke7

I have 3 solar panels on my roof, they heat the water very well and that's the problem, the heat generated at the taps is very excessive. The temperatute of the water is enough to burn you, we have young children which makes it very dangerous. Any suggestions, must be something wrong with the setup.

emaherx

mickburke7 wrote: »

I have 3 solar panels on my roof, they heat the water very well and that's the problem, the heat generated at the taps is very excessive. The temperatute of the water is enough to burn you, we have young children which makes it very dangerous. Any suggestions, must be something wrong with the setup.

Nothing wrong with your panels as such.

But you can get an anti-scald valve installed. You set your max temp and it will automatically add cold water before reaching the taps.

mickburke7

emaherx wrote: »

Nothing wrong with your panels as such.

But you can get an anti-scald valve installed. You set your max temp and it will automatically add cold water before reaching the taps.

I had an anti scald valve fitted last summer, but maybe it's not working now, can they seize up? Any valve brand recommendations if I need to change it?

mickburke7

mickburke7 wrote: »

I had an anti scald valve fitted last summer, but maybe it's not working now, can they seize up? Any valve brand recommendations if I need to change it?

It’s not working, talk to the installers or cylinder manufacturers for more advice or help their usually good.

Sleeper12

mickburke7 wrote:

I had an anti scald valve fitted last summer, but maybe it's not working now, can they seize up? Any valve brand recommendations if I need to change it?

You need to sort it this sooner rather than later. Thermostatic showers have a maximum temperature. You can damage the cartridge if the water coming inside is too hot hot. In fact it can damage regular spindler on a hot taps throughout the house

John.G

mickburke7 wrote: »

I had an anti scald valve fitted last summer, but maybe it's not working now, can they seize up? Any valve brand recommendations if I need to change it?

Caleffi have a Caleffi Solar Antiscald Valve 2527 which is rated for a maximum hot temperature of 100C. They also have a Caleffi Tempering Valve 5213 which is rated for a maximum hot water temperature of 85C, I presume other manufacturers have similar types. It would be interesting to see the make/model that failed on you.

mickburke7

See attached my set-up, I will need to get it replaced with a different valve. I also had a problem last summer that my header tank in the attic heated up which was very unusual as there is no return loop. Is it possible the cold feed pipe into the anti-scald valve was actually getting so hot heating the water in the header?

@ Sleeper 12 - Its funny you mention the thermostatic shower, I had big problems with it, I went through 5 cartridges, I thought it was to do with hard water in my area.

freddyuk

Could be debris that was not flushed out when fitted. You can adjust the outlet temperature using the red knob so have you turned it down at all?
If the solar has maxed out and given you 100c + temperature it could damage the valve. The solar should be limited to stagnate if it gets too hot. I very much doubt you have a bypass fitted so the solar controller should switch off the solar pump well before your cylinder gets too hot.
We cannot see the rest of the install so cannot comment further but your solar needs sorting first going by your comments of overheating.
How many tubes and how much stored water?

John.G

freddyuk wrote: »

Could be debris that was not flushed out when fitted. You can adjust the outlet temperature using the red knob so have you turned it down at all?
If the solar has maxed out and given you 100c + temperature it could damage the valve. The solar should be limited to stagnate if it gets too hot. I very much doubt you have a bypass fitted so the solar controller should switch off the solar pump well before your cylinder gets too hot.
We cannot see the rest of the install so cannot comment further but your solar needs sorting first going by your comments of overheating.
How many tubes and how much stored water?

As far as I know all anti scald valves have non return valves fitted to prevent any backflow/thermosyphoning etc. In vented systems antiscald valves have a very low tempered hot water output flow especially in a upstairs bathroom and "knacks" (illegal) to improve the flow include the removal of one or both NR valves.
As stated above, a heat dump should allways be fitted with a evacuated tube array but of course in most if not all cases, it isn't. I have a flat plate array with no heat dump but I have never seen the hot water temperature higher than 77C, I have my max cylinder temperature set at 80C.

The R156 is capable of a max temperature of 100C and does not have check valves (the R156-1 does), I dont think a different make of antiscald valve will solve your problem, I would ensure that the max cylinder temperature is set at a max of 80 to 85C.
https://uk.giacomini.com/prodotti/r156

freddyuk

I am guessing this is a vented system and the solar is boiling the cylinder so it is steaming up the vent pipe into the f&e tank? If the sensor has failed (T2) it is not measuring the cylinder temperature so not switching off the solar system. Or the controller needs re setting or replacing. Tubes can get to well over 120c and with three collectors serious heat is produced.