Solar Hot water systems!!

[madmat34]

Very funny gasguru!!!! Much rather pay the £5000.... I think not!!!!

I'm based in gravesend in kent where r u based in Essex??
Would be a superstar if you could pop and have a look, would cover your costs & time.

I told them I would take them to court & sue them for a full refund etc. they just said "see you in court then" .....So no joy there!!!
I would be happy just to get just my hot water up there at least that would be something.

called them again today they told me that...... they'd call me back in half an hour & .................. Still waiting!!! think I'll phone them everyday this week just for the fun of it.. haha

 

[Nigelo]

the bottom of the bolier is connected into the central heating system via a three port valve and yes the heating feed pipe is still hot (don't think that it should be hot at all unless I actually have the heating on or being called for by my room stat, the room stat is off!!)

I could easily be wrong but you may have hit the nail on the head.

Lets try this - A MID position valve has been fitted to your boiler system ie both HW and CH ports open when at rest. Thermo syphon, which requires no power whatsoever of course, then runs unobstructed from upper heat coil of HW cylinder and transfers heat to boiler / 1st part of CH circuit through open CH port. This cools water in the cylinder very quickly. I'm not a Plumber or Ht. Eng. so may be others could offer a quick fix to stop thermo syhpon if my analysis is correct

Hope his helps

 

[ChrisRoberts]

Drop me an email mate and we'll see what can be done.

========================
see forum rule 7

 

[oilman]

the bottom of the bolier is connected into the central heating system via a three port valve and yes the heating feed pipe is still hot (don't think that it should be hot at all unless I actually have the heating on or being called for by my room stat, the room stat is off!!)

I could easily be wrong but you may have hit the nail on the head.

Lets try this - A MID position valve has been fitted to your boiler system ie both HW and CH ports open when at rest. Thermo syphon, which requires no power whatsoever of course, then runs unobstructed from upper heat coil of HW cylinder and transfers heat to boiler / 1st part of CH circuit through open CH port. This cools water in the cylinder very quickly. I'm not a Plumber or Ht. Eng. so may be others could offer a quick fix to stop thermo syhpon if my analysis is correct

Hope his helps

It's worse than a mid position valve sitting in the middle, since if there is no demand from the DHW, the valve motors to CH fully open, and then waits.

 

[madmat34]

Oilman!!!!!! I think you've got it...
I don't really know what the 3 port valve does but I know that this is the cause of all my problems?????
I know that I have to have one but if it stayed on hot water rather than resting on cental heating would it be better or worse??
the pipework is as folows:
22mm feed from bolier to bottom of tank, back out slightly higher up back to 3 port valve... one side back to bolier other side back around heating system and then a return pipe 22mm from heating system.
I have a resol-b which tells the solar pump when to pump and when not to pump. but thats about all.
we do get very lovely mains pressure hot water when the tank is at 60 degrees and above but it doesn't last very long

Who knows what to do???? Not me I'm just a humble plaster with basic plumbing ,electrical and general building knowledge...lol

Another point???? you'll like this 1...... should the electrics have been given a part P cetificate?? mains and to do with water?? tricky!!

keep it going guys, would love to upset the company so more by being a pain

 

[Nigelo]

Oilman, I don't think you are quiite correct. Honeywell's mid position 3 port (V4073) does not automatically shut the DHW port (port B) when demand has been satisifed. In fact with no power supplied to the valve, the motor de-energises and returns under spring pressure opening port B. With power supplied, the last port of call (ie last to have been satisifed) remains open so could be either depending on demand and not mid position as I mistakenly believed. Info taken from Honeywell doc v4073aop.pdf

Mat, the circulation through the 3 port valve is very simple to understand:
Flow is from top of boiler (hottest) to Port AB of 3 port valve. Port B flows to HW cylinder / Port A to CH. Return from both cylinder and CH returns to bottom of boiler (coolest). Do check that valve is correctly fitted to flow not return and that flow enters valve at port AB/ port B goes to cyl / port A to ch.

 

[Kes]

Hi,

Isn't the point that this type of solar heating is not, and never was, intended to feed a central heating system? (Outside of a salesman's spiel, that is.) The sooner the system is completely separated from the central heating the better. Then some accurate measurements and setup tweaks can start.

Interesting thread, by the way, my roof, and wallet, is crying out for solar hot water!

Rgds.

 

[Nigelo]

Isn't the point that this type of solar heating is not, and never was, intended to feed a central heating system?

Well, yes and no. Yes for the size of Mat's system under discussion. No in the sense that collector area could be added specifically for CH provided a thermal heat store of appropriate size was fitted to match eg collector area 10/15m2 with THS of 1,000 litres.

The sooner the system is completely separated from the central heating the better. Then some accurate measurements and setup tweaks can start.

I believe that Mat's solar system IS completely separate from the boiler. The only item common to both appears to be the HW cylinder usually a 2 coil unit where the lower coil obtains heat from solar collector and upper coil obtains ocassional heat from boiler. The latter is provided to increase upper temp of cyl where necessary ensuring HW is available at times of peak demand. Aslo when available solar power is insufficient to cope with demand eg multiple showers in mid-winter.

To maximise availability of solar energy thus minimising boiler running costs, you increase your HW storage capacity to approx 70/100 litres per person.

However, Mat's problem appears to be heat leakage from the HW cyl by thermo-syphon from the UPPER coil back to the boiler vai the 3 port valve. If I am correct, I assume that a 2 port zone valve could be added to block the thermo syphon but I don't know if this simply addresses the symptoms rather than the cause.

 

[Deansplit]

Nasty experience - I am considering one - we have oil fired heating in N Ireland and with the hike of oil recently, the winter cost me £40-50 a week to heat a 3 storey Victorian pad on the sea front! Thought it'd be dear being solid stone walls but that takes the p**s!!! Now considering getting a pellet boiler (currently 22p/l as opposed to oil @ 37p/l and rising! Big initial outlay tho although grants available. Mmm, thought solar woul reduce it even more too...!

Good luck with naming n shaming them - true, I've threatened our ins co b4 after a lge theft with Watchdog & The Guardian, they soon paid up!

 

[madmat34]

Hey dean

Actually some of the systems are really good...But go to a really good company thats listed on clear skys web site.
A spoke to a guy at Sonnenkraft tthose boys really know there stuff.
Take a look at there web site, the only thing is with there system it would have to be underfloor heating. That would mean you gotta dig up all your downstairs floor lay the pipe and re-screed. Unless you got a wooden flooting floor & then jobs a good un'. The cylinders look like space ships very funky!!
Got my recipt today for my turbine for my roof, but its delayed till autum....


wow 15m2 of tubes thats a lot of tubin' & a thousand litre tank the water board would have a fit, we got a hose pipe ban...lol

 

[oilman]

Using mid position valves is generally bad news anyway, much better to use two 2-port valves. Everything is properly under control then.

 

[madmat34]

I take it with a 2 port valve its open or closed.... so no confusion???

 

[ChrisRoberts]

I still don't think the valve is a fault. I think it's more likely to be a set up problem. The sales team at Daft often tell the customers that the system will suplement heating but they never did. It could be just not enough heat in cylinder to start with or no non return valve on the solar pipework? Can U take some pics and post them for us ot see? that'd be nice.......

 

[Agile]

I think that he has said that he has a total of TWO panels and their combined area is less than THREE square meters.

Now I dont have the exact figures to hand and all the variables are very variable, mostly downwards. The received heat intput during a clear blue sky at noon is a peak of about 1.0 kW per m² in southern England. Allowing for say 15% losses thats 0.85 kW per m²

So he has LESS than 3 kW of heating ! Well thats almost enough to heat up his 170 li cylinder if its clear blue sky all day!

Tony

 

[ChrisRoberts]

Also Tony he has a torrent cylinder which is set to 60c we used to set them to 85c. As it's a thermal store. Then put a blender valve on the outlet to correct temp. I don't think he's making full use of what energy he's getting. I fitted a 300 litre cylinder with 30 evacuated tubes and that gets up to temperature by about 2 in the afternoon and was working well in the winter too, customer ran out of oil and still had a hot shower in december. Plus it never cost 10k+.
An average property will require between 2-5m of solar panels. This should be enough to provide 40-50% of the annual hot water requirements.
Solar can be used for space heating, but because the UK climate dictates that the days with least solar energy occur on the coldest days, only a small contribution of heat would be available.