Solar panels in this heat

Hijpo

Hi all,

We got evacuated tube solar panels installed a few months ago and with the sun we are getting lately the Dimplex Solcu-12 controller is telling me that the collector is over heating.

The temp of the water in the bottom of the tank in the hot press is 22 degrees and the top is 38 (as far as i can tell)

The switching valve indicator shows its still supplying the solution into the coil in the tank, and the circulation pump has been active the last hour.
The hottest the collector has gotten today is 206 degrees (going by the stats screen) and is currently 141 degrees.

Please see crudely drawing in paint for idea of whats on the controller display.
https://www.flickr.com/photos/109307248@N08/14287309527


In the manual it says that the pump will run until the max storage temp is reached. I have seen the tank heat to the high sixties so the fact that it hasnt gotten to above 40 has me puzzled. How is the solution in the panel cooled, where is the heat in the solution int he panel dissipated to?
Why hasnt the temp in the tank reached as high as it has before the collector overheated?

Dtp1979

Hijpo wrote: »

Hi all,

We got evacuated tube solar panels installed a few months ago and with the sun we are getting lately the Dimplex Solcu-12 controller is telling me that the collector is over heating.

The temp of the water in the bottom of the tank in the hot press is 22 degrees and the top is 38 (as far as i can tell)

The switching valve indicator shows its still supplying the solution into the coil in the tank, and the circulation pump has been active the last hour.
The hottest the collector has gotten today is 206 degrees (going by the stats screen) and is currently 141 degrees.

Please see crudely drawing in paint for idea of whats on the controller display.
https://www.flickr.com/photos/109307248@N08/14287309527


In the manual it says that the pump will run until the max storage temp is reached. I have seen the tank heat to the high sixties so the fact that it hasnt gotten to above 40 has me puzzled. How is the solution in the panel cooled, where is the heat in the solution int he panel dispated to?
Why hasnt the temp in the tank reached as high as it has before the collector overheated?

What pressure is the gauge showing?

Hijpo

Looking at the pump the two temp dials are reading 30C for the hot and 40C on the cold.
The pressure gauge on the right of the pump is reading 0 and what looks like a manually adjustable red needle is set at 70.

Dtp1979

Hijpo wrote: »

Looking at the pump the two temp dials are reading 30C for the hot and 40C on the cold.
The pressure gauge on the right of the pump is reading 0 and what looks like a manually adjustable red needle is set at 70.

It shouldn't be at 0. Your probably low on fluid therefore it's not going to circulate to the cylinder

Hijpo

Dtp1979 wrote: »

It shouldn't be at 0. Your probably low on fluid therefore it's not going to circulate to the cylinder

Low? I doubt thats normal after 6 months of service?

Ill give the installers a call on monday.

Pataman

I would top it up and check tomorrow.

Hijpo

Pataman wrote: »

I would top it up and check tomorrow.

I have nothing to top it up and wouldnt know how if I did heheh

freddyuk

Your system is stagnating and no heating of the cylinder is happening. You can check the overflow container below the expansion vessel - is there fluid in there?
If so the pressure valve has let the fluid out or the fluid has leaked elsewhere.
I any event you need to get the installer back FAST to replace the fluid and re pressurise urgently. He needs to check all the components are undamaged. If there is a leak in the system I would suggest you claim against the installers.
Most solar fittings are rated to 110c so anything that has been hit by higher temperatures needs checking for damage.

I would then suggest you have a by pass installed via a radiator to prevent over heating.

If the pump is running it should still pump fluid unless it is noisy (full of air) or damaged by the heat.

Your controller looks like it can be configured for a by pass system.

Hijpo

Thanks for the advice everyone.

Its 9am and the collector is already overheated at 170c. The pump is not circulating either and we have no hot water at present.

There is no fluid in the overflow container.

Trying to get through to the installers but they obviously wont be answering the phone until monday. Is there anything i can do until then?

Could it be that we have been a victim of "gelling" of the alcohol solution?

freddyuk

Unless you can introduce water into the system it will continue to overheat BUT DO NOT ADD WATER IN DAYTIME. The water will turn to steam with very bad results. You will just have to hope the system can withstand the heat. What make is it? When was it installed? Have you got a guarantee? Can you see any leaks on the roof? Is there an air vent on the panel at the top?? Any photographs of the system?

deandean

cover the panels with a tarp until you can get the system refilled.

Hijpo

freddyuk wrote: »

Unless you can introduce water into the system it will continue to overheat BUT DO NOT ADD WATER IN DAYTIME. The water will turn to steam with very bad results. You will just have to hope the system can withstand the heat. What make is it? When was it installed? Have you got a guarantee? Can you see any leaks on the roof? Is there an air vent on the panel at the top?? Any photographs of the system?

From the paper work the manufacturer is Joule and the make is Acapella (although on the paperwork he has written Acutelle) It was installed on the 17/12/13. I cant see any leaks from the ground and i dont have a ladder to extend to the roof too check for a vent. i can get a picture of the pump, the hoses entering the roof, the tank in the hot press and the controller if thats any good?

freddyuk

deandean wrote: »

cover the panels with a tarp until you can get the system refilled.

Is this a good idea? He has 200c on the roof and may be up a ladder. I would stay away unless you are competent. A collector is cheap compared to a broken neck

freddyuk

Hijpo wrote: »

From the paper work the manufacturer is Joule and the make is Acapella (although on the paperwork he has written Acutelle) It was installed on the 17/12/13. I cant see any leaks from the ground and i dont have a ladder to extend to the roof too check for a vent. i can get a picture of the pump, the hoses entering the roof, the tank in the hot press and the controller if thats any good?

It is a Joule kit. You cannot really do anything but send some pictures as that will tell us if the installer was at all competent. If he can't spell he may not be able to understand the installation instructions.
I would look at the roof and then the expansion vessel and the overflow tank in the attic + the pipework to the pump station and cylinder.

homewardbound11

Had the same with joule. There are solar chargers for filling. As your are under warranty. I would not fill it your self. The charging can take a while as the solar fluid ( food grade glycol)needs to be recirculated for a good while to remove the air in the system. This might be your problem as all the air might not be removed
I had mine go to the mid 160's( joule) and recharging was fine. Just make sure it is tested under pressure by the installer before leaving. Also keep any eye on the solar pressure . It should be 1.5 to2 bar. This will change As the panels heat but should never read 0 even in the night. There is also a flow sight glass you should be able to see the brown float or green float rise to 6 l/ min when the pump is circulating(approx 2l per panel If I remember)

Got all this info from YouTube . So you can search yourself.

So don't panic just yet.

Hijpo

While taking a pic of the pump i noticed some droplets on the underside. It feels like an oily substance, i am uploading the pics now.

https://www.flickr.com/photos/109307248@N08/sets/72157644886550910/

esox28

Installation looks good.

I had a problem with two installations of joules stainless steel piping, well not the pipe itself the fiber washers supplied with the kit, they expanded due to reaction to temp and glycol solution.

Get your installer to check that the washer haven't changed there shape, if this is the case I would then replace the entire set from installation, also get your installer to contact joule for advice.

Hijpo

From what i can see the only issue is the residue here https://www.flickr.com/photos/109307248@N08/14292349658/in/set-72157644886550910

and the dark patch the looks like dampness on the floor here https://www.flickr.com/photos/109307248@N08/14455783646/in/set-72157644886550910

I think its safe to assume there is little or no fluid left for the pump to circulate. Is there anything at all i can do to prevent further damage (if any has been done already) before i get through to the installer on monday?

My main concern would be the collector getting to hot and bursting, seen as the pump isnt circulating i dont think any components inside the house will be effected.

homewardbound11

esox28 wrote: »

Installation looks good.

I had a problem with two installations of joules stainless steel piping, well not the pipe itself the fiber washers supplied with the kit, they expanded due to reaction to temp and glycol solution.

Get your installer to check that the washer haven't changed there shape, if this is the case I would then replace the entire set from installation, also get your installer to contact joule for advice.

That oily substance is your glycol. The leak is most likely at the stainless tube to brass fitting at the station. Different heat coefficients of different metals will expand at different rates. Get your local plumber out if you cannot get the installer. They will fix the leak and rechrarge the station. 89 euro should cover it if there are no other issues.

Hijpo

Thanks for all the advice.

Ill get onto a plumber asap.

very much appreciated.

ccsolar

Hijpo wrote: »

Thanks for all the advice.

Ill get onto a plumber asap.

very much appreciated.

Hi
Stop what your doing climbing on roof's , re pressurising system.
You paid for a system to be installed correctly and it's NOT.
It's covered by warranty and if you interfere with it then the warranty is VOID.
Switch it off and contact the installer, the system is leaking at the joints as fibre washers were used, fibre washers are old school cheap installation and even if you replace them they will leak again after about 2 yrs unless you install a heat dump, it's a simple add on but it takes all the pressure off your solar system on a hot day.
You have also the option to upgrade the joints with better connections but these cost €5.00 each
We have been using them for years now and never had any leak.
Unfortunately your plumber probably just bought a kit from joule and fitted it, simple to do until the problems start, repressurising the system will solve the problem for a few months but by then it will be out of warranty on the labour and you will be back here again..

Cc

Hijpo

ccsolar wrote: »

Hi
Stop what your doing climbing on roof's , re pressurising system.
You paid for a system to be installed correctly and it's NOT.
It's covered by warranty and if you interfere with it then the warranty is VOID.
Switch it off and contact the installer, the system is leaking at the joints as fibre washers were used, fibre washers are old school cheap installation and even if you replace them they will leak again after about 2 yrs unless you install a heat dump, it's a simple add on but it takes all the pressure off your solar system on a hot day.
You have also the option to upgrade the joints with better connections but these cost €5.00 each
We have been using them for years now and never had any leak.
Unfortunately your plumber probably just bought a kit from joule and fitted it, simple to do until the problems start, repressurising the system will solve the problem for a few months but by then it will be out of warranty on the labour and you will be back here again..

Cc

Thanks CC.

I havent gone near the system and a plumber friend advised me of the same with regards leaving it to the installer. When you say switch it off, how might i do this and is it essential?

I will enquire about the heat dump and upgrading the connections on monday when i get the installer on the phone.

ccsolar

Hi
Can you post a picture of the bottom of the tank in the hotpress where the solar pipes enter the tank,
Try and include most of the tank in the photo
If your getting the installer out we might as well get a look at the full installation to maker sure there is no other faults.

Cc

ccsolar

Hijpo wrote: »

Thanks CC.

I havent gone near the system and a plumber friend advised me of the same with regards leaving it to the installer. When you say switch it off, how might i do this and is it essential?

I will enquire about the heat dump and upgrading the connections on monday when i get the installer on the phone.

Their should be a spur switch supplying power to the system, just pop a screw driver into the side of it and the fuse will pop out, ( Only do this if your competent)
Or switch off mains at fuse board first.
You are trying to protect the circulating pump by doing this.....
Your lucky as these problems normally only arise after 18 mts and out of warranty
Cc

Hijpo

ccsolar wrote: »

Their should be a spur switch supplying power to the system, just pop a screw driver into the side of it and the fuse will pop out, ( Only do this if your competent)
Or switch off mains at fuse board first.
You are trying to protect the circulating pump by doing this.....
Your lucky as these problems normally only arise after 18 mts and out of warranty
Cc

instead if whiping out the fuse I turned the immersion on to bring the temp in the tank up which should tell the pump its not needed and stop it circulating, should that work? Ill get the pic up now.

Hijpo

Its a 300l https://www.flickr.com/photos/109307248@N08/14293111379

Here is a closer on of bottom https://www.flickr.com/photos/109307248@N08/14479745795/


The damp patch under the insulation on the pipes is a drip coming from the stop cock on the right of the tank.

ccsolar

Hijpo wrote: »

instead if whiping out the fuse I turned the immersion on to bring the temp in the tank up which should tell the pump its not needed and stop it circulating, should that work? Ill get the pic up now.

That won't work as the immersion is higher than the solar coil unless you have a T3 thermostat installed.
It all depends on the individual set up
If your not confident in poping out the sour fuse , don't worry about it
Just get the installers back ASAP
Cc

Hijpo

Just an update.

Got through to them this morning and the earliest they can get here is thursday. I told them the temp of the collector, the leaking glycol and the 0 on the pressure gauge, that i was concerned that there is nothing to keep the collector cool and that the pump could be damaged etc and he said that it should all be fine and to leave it the way it is.


Thanks again lads.

freddyuk

That's customer service for you - making more money is more important than looking after customers who have paid already.

I would be looking for a new pump and expansion vessel as a minimum. These are likely to have suffered/be suffering damage from the extreme heat. You should have a warranty card and details of the warranty? If the system is left to stagnate I can guess Joules will run a mile. If the system was not installed as per the Joules instructions (and I can guarantee it was not) then you may have to go after the installers. I would start preparing your case. If they just try to replace the glycol insist on a damage report based on extended stagnation due to improper installation.


This is taken from the Joules certification:

3.5 HIGH TEMPERATURE CONDITIONS
Joule Zitrec Solar LC, used with the Joule Solar
Collector Heating Systems is mono propylene
glycol based heat transfer fluid, blended with
high temperature corrosion and scale inhibitors,
tested to 300°C.
Continuous temperatures in excess of 137oC will
cause the gradual degrading of the antifreeze
solution and its inhibitor properties and over time
will also cause damage to the solar pump station
(rated at 160 oC max.), and the expansion vessel
diaphragm (rated at 100⁰ C max.) in the system.
The Joule Control Panel uses the following three
functions to prevent stagnation in the system
from occurring:
Thermostat Function
This function allows the controller to control the
circulator supplying to the hot water system
depending on a pre-defined temperature
difference.
When the temperature in the cylinder exceeds
the defined ‘on’ value (typically 80oC), the pump
is switched on until the temperature difference
falls below the ‘off’ value (typically 60oC). This
cycle will continue until the collector temperature
has been reduced.
Stagnation Reduction Function
This function delays the end of the cylinder’s
loading phase in order to reduce, or even to
avoid, the system’s stagnation times at high
temperatures. This function causes the pump to
be stopped repeatedly, and only briefly switched
on again when high collector temperatures arise.
With higher collector temperatures, the efficiency
decreases significantly, thus loading takes longer.
This delays the beginning of any stagnation time.

Joules do show a by pass system - "if required" which I think it is.

The complete document can be viewed here http://www.jouleuk.co.uk/NSAI/303/

Hijpo

I think i will get directly onto Joule, explain what has happend and ask what they would do to a system that has gone through the senario that mine has. Atleast that way i will know if they are cutting corners.

Hijpo

Last week i got onto Joule to ask what i should request the installers should do so they dont cut any corners, Joule told me to just let the installers work away with what they think is necessary. Chap came and repressurised the system last wednesday.

Everything was fine until today when i went out to the car and saw steam coming from the left side of the first panel (we have two in series) where the hose connects to the panel. Collector is now over heating at 138. The pump is still circulating and the temp in the bottom of the tank is 46.

They are coming back tomorrow.

freddyuk

But we KNEW that is what they would do. Did they go on the roof or just re pressurise until the joint opened up again? So now if your system was not damaged before it most likely is now. You need new pump, expansion vessel etc. as I said before as these are rated to only 110c.
If you don't get it done properly keep evidence and write to Joule.

Hijpo

No they didnt go on the roof, they just re pressurised.

esox28

esox28 wrote: »

Installation looks good.

I had a problem with two installations of joules stainless steel piping, well not the pipe itself the fiber washers supplied with the kit, they expanded due to reaction to temp and glycol solution.

Get your installer to check that the washer haven't changed there shape, if this is the case I would then replace the entire set from installation, also get your installer to contact joule for advice.

As I said before your fiber washers in stainless steel piping are shot. Get them replaced.
From your original leak at the pumping station there's now a leak at the panel.

Ring joule again and get them to send you some, and get installer to replace.

ccsolar

Yes
Get all the fibre washers replaced and this will solve your leak.
We will then see you back here again next year with the same problem unless you deal with the overheating of the system.
It will be out of warranty next year and to put things right will cost you €400+.
1 of the main reasons you system is overheating is the size of your hot water cylinder.
Get that heat dump fitted...
Cc

esox28

ccsolar wrote: »

Yes
Get all the fibre washers replaced and this will solve your leak.
We will then see you back here again next year with the same problem unless you deal with the overheating of the system.
It will be out of warranty next year and to put things right will cost you €400+.
1 of the main reasons you system is overheating is the size of your hot water cylinder.
Get that heat dump fitted...
Cc

No.
How does the ops system need a heat dump, from what I can tell its two panels and 200ltr tank hardly overheating due to excessive temp generated but more likley lack of heat transfer fluid leaking out.

Hijpo

300ltr tank and two panels.

The fluid leaking at the pump meant the panels were not being cooled at all.

The washers were replaced on the pump and sealant applied to the connections. The panels reaching 200+ for a week and a half destroyed the washers on the panels so they were replaced today. He said anything over 150 would wreck them so 200+ would have cooked them all together.

I dont think he realised/was told that they were hitting 200+ for so long.

ccsolar

esox28 wrote: »

No.
How does the ops system need a heat dump, from what I can tell its two panels and 200ltr tank hardly overheating due to excessive temp generated but more likley lack of heat transfer fluid leaking out.

If the op is not using enough of the water been heated by the solar the temperature will eventually build up forcing the solar system to shut down
This in turn will result in the solar system overheating again, the fibre washers come under increased pressure as the system expands and contracts.
Over a period of time the fibre washer becomes compressed resulting in some of the joints weeping.
The capacity of the ops cylinder will also increase the likelyhood of this problem happening again over time.

Cc

esox28

ccsolar wrote: »

If the op is not using enough of the water been heated by the solar the temperature will eventually build up forcing the solar system to shut down
This in turn will result in the solar system overheating again, the fibre washers come under increased pressure as the system expands and contracts.
Over a period of time the fibre washer becomes compressed resulting in some of the joints weeping.
The capacity of the ops cylinder will also increase the likelyhood of this problem happening again over time.

Cc

I understand the principles of stagnation.

I've done four schools three years ago with 300ltr tanks and 6*mtrs of panels with all fitted with aux. Heat dumps, as per listed specification. I inspect each system anually and not one controller shows any operating time for aux. Valve and pump in operation.

In 40 + domestic installations I've never fitted a heat dump.

ccsolar

esox28 wrote: »

I understand the principles of stagnation.

I've done four schools three years ago with 300ltr tanks and 6*mtrs of panels with all fitted with aux. Heat dumps, as per listed specification. I inspect each system anually and not one controller shows any operating time for aux. Valve and pump in operation.

In 40 + domestic installations I've never fitted a heat dump.

What controller are you using?
Does it log the time the Aux is running?
What make of 300 litre tank did you use?

freddyuk

Are we talking flat plate here?? 60 tubes on a school during weekends and holidays should easily get to 60c +? Unless there is something wrong with the system or you reset the maximum temperature limit.

esox28

Kingspan flat plate.

Kingspan controller branded but a steca sc ( not sure which model)

HM pro. 300ltr tanks dual.

com. Thermo valve set to 42*c

John T Carroll

esox28 wrote: »

I understand the principles of stagnation.

I've done four schools three years ago with 300ltr tanks and 6*mtrs of panels with all fitted with aux. Heat dumps, as per listed specification. I inspect each system anually and not one controller shows any operating time for aux. Valve and pump in operation.

In 40 + domestic installations I've never fitted a heat dump.

I have 2XFP + 150 Litre cylinder and use practically no hot water at the weekends as not at home. My system has never stagnated (no heat dump fitted) and the max cylinder temperatures observed were/are 76C/77C, I have the max cylinder temperatur set at 80C.
The E.Tube however will reach very high temperatures due its superior efficiency, I calculate that an E.Tube will reach 200C with fairly modest solar radiation of 650 watts/M2 and 15C ambient, the FP will only reach 117C under the same conditions.
I think it is very unwise not to fit a heat dump with an E.Tube system.

househero

Hijpo wrote: »

Solar

Great Photo Steve
https://www.flickr.com/photos/109307248@N08/14314654869/

You should post up the name of the installer to warn others. It should not have done that. Tell them you will remove their name after they fix the system and you can praise them on here when all fixed for their professionalism in dealing with the matter.

Stick & Carrot = Results

Hijpo

househero wrote: »

Great Photo Steve
https://www.flickr.com/photos/109307248@N08/14314654869/

Thank you, very much appreciated

househero wrote: »

You should post up the name of the installer to warn others. It should not have done that. Tell them you will remove their name after they fix the system and you can praise them on here when all fixed for their professionalism in dealing with the matter.

Stick & Carrot = Results

I wasnt certain if it was against the rules or not so i took the easier route and left it out. Its all good now, panels havent gotten any higher than 68 and we have hot water without using the immersion.

I would imagine its been slowly leaking away since installation as i remember the panels reaching 100 and odd before, even though this is the first time they have seen direct sunlight for prolonged hours.

Hijpo

Over heated again today.

Gave them a call and their going to fit the heat dump as previously suggested.

He said that this literaly dumps hot water from the tank into the gutter to drop the temp in the tank.

It is a fix but how much water are we talking about here considering the amount of times its over heated and the length of time the temp will be 130+?
Worried with water rates coming in.

ccsolar

Hijpo wrote: »

Over heated again today.

Gave them a call and their going to fit the heat dump as previously suggested.

He said that this literaly dumps hot water from the tank into the gutter to drop the temp in the tank.

It is a fix but how much water are we talking about here considering the amount of times its over heated and the length of time the temp will be 130+?
Worried with water rates coming in.

Hi
That's just pure stupid, it's that stupid it must be a windup.
You could be looking at 300 litres per day dumping into your gutter
Who's going to pay for that if your on a water metre
Why don't they just dump to the central heating system
Pure cowboys
Cc

Hijpo

I know dumping any water down a drain is rediculous carry on.

I was reading about dump rads?

I would imagine they will need to upgrade the controller, run new piping, install valves and temp sensors?

John T Carroll

Hijpo wrote: »

I know dumping any water down a drain is rediculous carry on.

I was reading about dump rads?

I would imagine they will need to upgrade the controller, run new piping, install valves and temp sensors?

I posted this on 9/7/2014. "I think it is very unwise not to fit a heat dump with an E.Tube system." I really think that I should go a bit further and say that all installers of E.Tubes should quote their systems with a heat dump (no, not down the drain) fitted as "standard" and then advise the customer of the consequences of not doing this, despite the "savings" of not fitting it.
Of course everyone would have to sing from the same hymn sheet when quoting for jobs and this just wont happen in real life except its made mandatory, which is very unlikely.

freddyuk

Hijpo wrote: »

Over heated again today.

Gave them a call and their going to fit the heat dump as previously suggested.

He said that this literaly dumps hot water from the tank into the gutter to drop the temp in the tank.

It is a fix but how much water are we talking about here considering the amount of times its over heated and the length of time the temp will be 130+?
Worried with water rates coming in.

I can get someone to do this for you if you are in the Dublin/Offlay area. Don't even consider letting that numpty near your system. It is a simple kit to bypass your flow and return pipes into a radiator at a set temperature. He will also correct any faults that exist.

Hijpo

freddyuk wrote: »

I can get someone to do this for you if you are in the Dublin/Offlay area. Don't even consider letting that numpty near your system. It is a simple kit to bypass your flow and return pipes into a radiator at a set temperature. He will also correct any faults that exist.

Sounds good but I'm in the south. Thanks for the message.