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Thermal Panel issues

  • 26-05-2023 5:31pm
    Registered Users Posts: 24,762 ✭✭✭✭

    Hi all,

    we’re in a relative new build (2017) and the house was built with thermal solar panels included. However we have issues with these panels whenever the weather gets good, like today. The panels continue to heat the water regardless of the water temp. Today I noticed the 2 tanks in the house were at 77 and 74 degrees respectively. This isn’t the first time that it has happened.

    Previously we’ve contacted the installers of the panels themselves. However their take on this was that this is how the panels are meant to work and we just need to run off the hot water. That the panels getting up to nearly 80 degrees and the hot water being completely unusable was not an issue.

    The other problem is that it’s starting to damage the whole set-up in the house. We have a water pump that won’t turn off because the washers are damaged due to the heat of the water. We’ve had that fixed but any fix is temporary while the water is able to get that hot and the pump is again not turning off.

    Does anyone know of anyone who could service the panels and the system to make sure it’s operating correctly? I’ve found a few places online but when we’re talking a few hundred euro then recommendations are very helpful!



  • Registered Users Posts: 2,529 ✭✭✭bullit_dodger

    My knowledge of plumbing isn't great but that seems a bit high. I guess another option to put on the table is you could look at installing a thermostatic valve.

    Thermostatic mixing valve - Wikipedia

    Install that on the outlet of the immersion tank so that all the water consumed downstream from there is a more acceptable (say) 55C? Not saying that this is the best solution but something to consider.

  • Registered Users Posts: 24,762 ✭✭✭✭molloyjh

    Thanks. Def an option to look at if we can’t get the issue resolved.

  • Registered Users Posts: 65,404 ✭✭✭✭unkel
    Chauffe, Marcel, chauffe!

    Yep what @bullit_dodger said. I think it's called an anti scalding valve.

  • Moderators, Home & Garden Moderators Posts: 6,090 Mod ✭✭✭✭graememk

    Yep there should have been a thermostatic mixer valve to mix down the hot water to a safe temperature. Also known as a anti scald valve.

    Two bonuses, water doesn't scald you.

    Hot water lasts longer too as it's blended down with cold water.

    That is the fix for it,

  • Registered Users Posts: 24,762 ✭✭✭✭molloyjh

    Thanks a mil folks.

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  • Registered Users Posts: 65,404 ✭✭✭✭unkel
    Chauffe, Marcel, chauffe!

    Will you please update here how you are getting on and how much it cost you to get someone to come install an anti scalding valve?

    My own solar thermal doesn't have an anti scalding valve either (the installers skipped on this, they shouldn't have) so on days like this the water gets a bit over 60C. Only adults and teenagers in the house, so nobody will get burnt, but would be better if that would be blended down to about 50C or so max

  • Registered Users Posts: 24,762 ✭✭✭✭molloyjh

  • Registered Users Posts: 1,406 ✭✭✭dathi

    i have one on my solar water system have it at the cylinder they are very easy to install and were a requirement for any of you that got a grant to install the system i blend my water down to 46 degrees. the other thing is that in the menu of the solar controller you can set the max temperature that the water will rise to before the system either heat dumps or stops circulating

  • Registered Users Posts: 65,404 ✭✭✭✭unkel
    Chauffe, Marcel, chauffe!

    Aye I know. And I did get the grant and the system was installed in 2016, so should have been fitted with the valve. The max temp of the water in the solar thermal system is set to 63C which is ok.

  • Registered Users Posts: 139 ✭✭alexf1

    Don't go fiddling with that on a hot sunny day either... *recalls the very hot sunny summers day when steam at pressure came spitting out of the pipe when trying to connect the cylinder on a new build. Water was hot enough to cut you arm clean off, readout showed 120 degrees c. There was lots of shouting between plumber and solar tube installers.

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  • Registered Users Posts: 4,432 ✭✭✭Gerry

    Best thing is to get a hot tub or pool installed to make best use of the excess hot water.

  • Registered Users Posts: 299 ✭✭JayBee66

    The control panel on our solar thermal allows us to set a maximum temperature. We set ours to 65C. It does go a little higher in the summer but I've never seen it higher than 68C.

    Do you see a control panel near the hot water cylinder?

  • Registered Users Posts: 3,398 ✭✭✭randombar

    We've a pressure valve on the hot tank that spits out the water if it goes above 60 degrees. I also have an expansion tank but the bladder has blown in that twice.