Ecosmart solar hot water troubles

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Ecosmart solar hot water troubles

Postby jimbo » Tue Feb 23, 2016 11:48 am

The house i am renting has an electric boosted Ecosmart solar hot water system (open loop) with a 400L tank and 3 flat panels on the roof. It usually works fantastic as we have been here since August with the electric booster turned off and never had issues.
2 days ago we noticed the water a little cooler so started monitoring everything. Yesterday it was 30 degrees with quite a few hours of sun but at night the water was cold. During the day i could feel still hear the pump and the pipes going to and from the panels was warm but right where the Solar return enters the tank was cold.
I turned the booster on last night and we have hot water again but today the solar return still feels coder than the other pipes.
Is there any way i can test the pump is actually pumping? Being a rental I can get it fixed but I don't want them to call a sparky out only for him to say that the problem is the booster being off.

Thanks

BTW today it's 37 degrees and sunny. Usually the pressure relief valve would be dumping water by 1pm and that's without the booster on at night.
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Re: Ecosmart solar hot water troubles

Postby Gordon-Loomberah » Tue Feb 23, 2016 11:53 am

Maybe there's an airlock somewhere- hard to say if that is likely without being able to see the layout though.

If it was my system, I'd crack the fittings at the pump outlet and see if it was actually pumping (after turning the mains off if is it town pressure, not gravity fed), but it's up to you how far you want to investigate, since it is a rental property.
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Re: Ecosmart solar hot water troubles

Postby jimbo » Tue Feb 23, 2016 12:10 pm

We are on tank water.

The weird thing is 3/4 down the return pipe is hot but the last 20cm is cold. Right b4 it inters the tank there is a U bend in the pipe and that is where it is cold.
The panels are directly above the tank.
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Re: Ecosmart solar hot water troubles

Postby Gordon-Loomberah » Tue Feb 23, 2016 12:18 pm

Sounds like the pump isn't working, either due to being full of air, or stuffed in some other manner. I assume there is enough water in the tank- might be worth checking.
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Re: Ecosmart solar hot water troubles

Postby APR » Tue Feb 23, 2016 2:55 pm

jimbo wrote:BTW today it's 37 degrees and sunny. Usually the pressure relief valve would be dumping water by 1pm and that's without the booster on at night.


Hi Jimbo, do you turn the pump [EDIT: your main water pump supplying the house] off at night?

One scenario......

Many solar HWS pumps are only capable of around 2.5 to 3 metres of head. If air gets into the system it is possible for the pump to not be able to push water to the collectors.

I expect there would be an air bleed valve on the collectors.... or at least a pressure relief valve. If you have turned the pump off overnight, there is a chance that air might have been sucked back in past this valve and the system could need bleeding. Under normal pressure from your main water pump, you could expect any air in the panels to be expelled.... but, who knows. An air relief valve may be fitted to the panels, and it should expel any air, but it could be faulty or not fitted to that system.

With your main water pump running, and in the morning before the panels heat up so you cannot be scalded, I would hop on the roof and operate the overpressure valve to see if any air comes out. If it does, operate the valve until you have a steady flow of water coming out.

Hopefully, this may be all that is required.

EDIT: THinking this through further, it may be necessary to crack the return line down near the HWS circulation pump to also expel any air in the return line.
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Re: Ecosmart solar hot water troubles

Postby jimbo » Tue Feb 23, 2016 3:52 pm

Nope pump stays on all the time.

When i cracked the solar return line (House pump off) and let some water out almost straight away steam started venting from the pressure valve on the roof. I have tried cracking the lines with both pumps on but so far no difference. It has become cloudy this afternoon so can't do much.
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Re: Ecosmart solar hot water troubles

Postby jimbo » Sun Feb 28, 2016 8:13 pm

I gave the pump a firm tap with my fist and it instantly started making a different noise and pumping water. My guess is it had an airlock.
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Re: Ecosmart solar hot water troubles

Postby jimbo » Thu Jun 16, 2016 12:03 am

Update!

The hot water has been working great but I have noticed lately that when its a cold night at 5 degrees or less the panels dump their water but at the same time are filled back up again by the pump, this is cycling the houses pressure pump every 20 seconds or so which has become very annoying and probably using a fair bit of power. I'm not losing any water as it just dumps on the roof and back in the tanks.

Any idea what is going on? Last night i just turned the tap off to the HW unit which stopped the cycling but I then had to bleed the system to get the solar working in today's sunshine.
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Re: Ecosmart solar hot water troubles

Postby Privatteer » Mon Jun 20, 2016 6:30 pm

Sounds like it has an anti-freeze option that's kicking in too early. The systems I've worked on just circulated some of the hot water back from the tank. From what you have described it must have some sort of automatic valve?
I would expect its either its going to be controlled by the hot water sensor or have another temp sensor built into the valve.
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