Solar water heating system playing up

Haven't noticed much in the winter as mainly been using domestic cycle with solid fuel. Now the weather is warm have noticed not much heat from the solar panels. Temp this morning at the panels was 74c and in the tank 19c. Checked in the loft where the hot water tank is and its luke warm, looked at the pressure and its 10 bar which is normal, green light on saying that pump is on to cycle the water around. No leaks that I can see. System is quite old but always been working and we have it serviced every 2 years as per installer.

Any ideas what I may be missing?

Reply to
les
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In message , les writes

Just because the light's on, doesn't mean that the pump's running, does it ?

Reply to
geoff

Water circulation... Lights on, no one at home. B-)

Reply to
Dave Liquorice

Places to start checking would include: power is reaching the pump the pump actually pumps the solar panel circuit hasnt leaked empty

NT

Reply to
meow2222

Will check the pump in the morning as i cant make the system come on at the moment (temp falling) Did check electric to the pump and yes there is, water in system is ok. Cant see any thermostat on the system as that was my next step. Costs about =A3200 just for the company to come out. Have a pump I got a year ago to replace in my old house, its brand new, still boxed but it is a central heating pump, a Wilo Gold RS50. The pump on the solar system has a label on it that says something like Unit5 but cant find that make on the net?

Reply to
les

not much point trying to solve the problem until you know what the problem is. It could just as easily be other things.

NT

Reply to
meow2222

How many months saving is that down the drain ?

But you still haven't checked to see if the pump is running, have you ?

Reply to
geoff

Thats why am asking advice on here. Step by step.

1) Does the pump work - will know tomorrow - no way of switching it in on a solar and dont want to start isolating it just to see if it pumps, weather looks good tomorrow, if pumps not on or failing then will replace it. 2) Is there water in system - Yes there is and have 10 bar of pressure. 3) is there a thermostat, could it be faulty - really not sure hence asking on here. 4) if pump faulty what type is it - found out now its a Myson Unit 5 Code 04/88 (presume that means date of manufacturer) U5C252 5) Can I replace it with my new Wilo Gold RS50 - not sure can i?

Thats as far as I have got trouble shooting.

Reply to
les

10 bar seems really high to me. That'll find a leak instantly though. Sure it's not 1.0 bar? How did you get it that high?

Gordon

Reply to
Gordon Henderson

Sorry Gordon Typo

Reply to
les

Yes dave am starting to think circulation ie: pump but not sure how solars work, ie: The panels reach a temp and something makes them switch the pump on - so there must be some sort of thermostat but cant find it, the problem is if its not the pump then it may be the thermostat where ever it is, and maybe a call to the installer - ouch expensive - thats why am hoping its the pump, can do that myself!!

Reply to
les

OK!

I'm about to DIY a solar water system, and it's not rocket science if you know a bit of plumbing. There ought to be a thermostat near the exit of the panel connected to the pump - which basically turns the pump on & off. However, it may be a bit more complicated if it's an anti-freeze-less system - there might be a controller to run the pump every now & then during freezing weather, although that's wastefull to me...

Calling the company in would be my last resort - £200 will piss away any potential savings this summer! So find the thermostat and pump and check them...

You may be able to force the pump on by turning the thermostat right down, or even wiring it out of the circuit entirely - depending on how accessable the wiring it and how competent you are with electrickery...

Gordon

Reply to
Gordon Henderson

Thanks Gordon Had a good look and there are 2 wires which come in from the solar panels through the roof and on the roof is a small box so either the thermostat is in the box or on the other end near the pump - will investigate tomorrow. The system is donkeys years old, and I guess the pump is the original one, its one of the early ones, ie: no tubes There is antifreeze in the system, thats renewed everytime the service is due. Pretty confident with simple plumbing and electrics, and will try and solve it before calling in the troops. Thanks guys for your help thus far.

Reply to
les

That domestic solar power is expensive, crap and doesn't stay working efficiently for long?

Reply to
The Natural Philosopher

Didn't pay for it, so cost me nowt, was on the house when i bought it.

Reply to
les

Neatly negating the past two years solar gains...

Its almost as good as Madoff.

Rip someone off for 2 granmd to install a system whose payback might at=20 best be 8% ROI, then charge em 10% of capital after it fails, every year =

or so.,.

Reply to
The Natural Philosopher

your suggestion is the??

Reply to
les

how often is that? wonder what it costs per year

NT

Reply to
meow2222

Has the green light gone off now that evening is approaching and the panels cooled down? If so that indicates the control system is working as it should, assuming tha the green light tells you when the pump shoud be running not that the system is just powered up...

You say you know the system has water in it. Are you sure have you bled it at the highest point (there should be a bleed valve there) and got water out. You can have 1 bar of pressure with air or water...

Reply to
Dave Liquorice

That's the best way to have it fer sure..

Reply to
The Natural Philosopher

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