Solar collector t&p valve excessive tripping

[protech]

Look, let’s cut the crap here. Are you saying that YOU regularly install an active-indirect system sized for 2-4 people for the equivalent price of $4000 on a daily basis or not. Because I, and most of my legitimate competitors do. That's out the door. Materials, Labor, Building Permit, Delivery.........everything.

Yes, or no. If no, what's your average price for the above.

Ahh but I quoted the price an installer or shrewd diy-er could buy it for also, and the installation cost would depend on local circumstances. Most hoses here are at least 2 story which is more risky to install on so it would cost more here. So the cost of $3592 +$1000 for installing it isn't far off your price of $4000 and this is for a premium branded product (not that i'm saying yours isn't). For a non branded system it would be up to $1000-$1200 less. I'm often under cut by £1000 - £1500 but their the people that phone up a year later when the company that installed it have done a runner or folded and reset up under a similar name without the liablities, with a system that was shodily installed and on the cheap, non solar rated components, such as central heating pump, pressure vessel soft soldered pipe work, heating pipe insulation, pressure relief into the house,... I'm sure you see your own horrors there.

Plus I also pointed out that you could install a simple indirect system for $1500

[protech]

No, it can't. Well not in Florida anyway. The collector loop will not be in the ideal growth range for enough time for that to occur. We get just a few days out of the year that the loop isn't sterilized.

Legionellae can still develop, it's a bacteria and given the right conditions could rapidly develop. The Regs here will not allow any contamination or possible contamination to backflow into the cold water supply. so that could depend on the materials the water is sitting in ie the solar panel piping material, the storage tank

[flamefix]

Your regulations (known as "codes" state side) make no sense.

You’re saying they don't want hot water (fluid category 2) from the open collector loop to be siphoned back into the municipal supply, so you should replace it with a more hazardous fluid (category 3)?

I think you're misrepresenting or interpreting what I am saying. and to clarify some of your points I have posed the question to the regs here so some things i'll get back to you on, and if i'm right or wrong I'll freely admit it publicly however; I am talking about my opinion and the regs here in the UK and I am not saying you are wrong to do what you are doing in any way, I have only said It wouldn't be allowed here (which I am confirming) and I 'personally' don't see the need.

your point above doesn't make sense either because the collector and the cylinder are as one the fluid in the two freely circulate they could gravitate if the pump wasn't on and if there are check valves then these could fail.

Now an indirect system is less risk because there is a physical barrier between the two fluids, be it the coil a cylinder within a cylinder or a plate heat exchanger.
That said I have clearly stated the cylinder holding the hot water must be heated to 60c. or be capable of heating to 60c to kill any legionellae.

here is an article relating to preheated water that is heated by solar and either flows to a hot tap if at the required temperature or is then passed through a combi boiler on the cold inlet side to be heated by the boiler. Another system I am not a fan of however,
http://www.wras.co.uk/Preheated-Water.htm

[flamefix]

Look, let’s cut the crap here. Are you saying that YOU regularly install an active-indirect system sized for 2-4 people for the equivalent price of $4000 on a daily basis or not. Because I, and most of my legitimate competitors do. That's out the door. Materials, Labor, Building Permit, Delivery.........everything.

Yes, or no. If no, what's your average price for the above.

no I am not saying that nor have I . I don't know what you purchase your system for and or your mark up for profit and labour content. All I have told you is the cost of the items as they are here, I am not saying what you can install them for and make the level of profit you require because I don't know your cost base. I have stated that you can buy an indirect system a lot cheaper than I believed you thought.
The systems here are integrated differently to the ones you have described in that they are connected to the central heating system, they are installed at height requiring safety platforms access towers and insurances and other factors are likely different here to there, so a true comparison on installed costs is difficult to compare equally, whereas the material cost isn't. I also don't know how local factors influence things for example It's cheaper for me to buy a Mac from the US than in the UK its the same bloody machine though. It might be you buying solar equipment is more or less expensive than buying it here.

However for your information a premium system with evacuated tubes 80 gallon cylinder (tank) as I described installed and warranted is $8600 a flat plate version is $7500 but equally a perfectly good quality system could be installed for $5750

That's based on my input costs but without your rebates, as I have no idea what they would be.

Why are you not also comparing your system to the integrated tank and collector system that you can get for far cheape,r than the system you fit that I have also given information on?

No, it can't. Well not in Florida anyway. The collector loop will not be in the ideal growth range for enough time for that to occur. We get just a few days out of the year that the loop isn't sterilized.

I'm not going to argue it's your professional opinion and I respect that, I am not fully convinced there is no risk, so personally I'd rather not take the risk given there is an alternative option.

[mkiernan]

There are a few things that will cause that condition to occur. I know of a plumber in central Florida that specializes in that sort of thing. You should give him a call. <whistling and twittles his thumbs>

protech is very right, do not use a t&p valve any where near the collector.
t&p valves are set to go at 210f as per ipc.
you only need a pressure relief valve.