Roger,
There is one issue people might see as the weather gets colder with ET systems. Mine uses a 315ltr stainless Everlast tank which is well insulated,as are the pipes. What is not insulated on many systems, regardless of brand, is the actual tank outlet coupling, where the Tank temperature sensor is located. If it isn't insulated it should be, or it is likely temperature sensed will not be correct & the pump will run almost comtinually, particularly in the later afternoon when the ambient temperature is falling, but the tube still working well.
I noticed this problem on a friends system recently. Basically, if no hot water has been used for a while, the outlet fitting will cool appreciably and register a tank temperature which could be as much as 20degC lower than it should. The result is the solastat controller sees the tank as being more than 12degC below the manifold & starts the pump. No matter how much it circulates the tank water through the manifold, the difference between the tank & the manifold won't get to the 6degC pump cutoff.
To get a correct tank temperature reading, one can open a hot water tap for a short time, which will bring the fitting containing the sensor back up to temperature, however this won't fix the pump duty cycle problem for long. The answer is to ensure the fitting & sensor slot areadequately insulated right from the tank to where the hot water pipe insulation starts. Easy to do with isulating foam from plumbing suppliers or even Bunnings, using a Stanley knife & some cable ties.
Having seen a few different systems & instals now, it is pretty obvious most plumbers either don't read the instal instructions, or disregard them. (I've been visiting too many houses lately as our young ones are house hunting & I get dragged along to look them over) I've seen about 6-7 different places with ET systems fitted & only one was properly insulated. The other common instal failing I've seen is the pumps mounted upright. They're supposed to be mounted wither horizontally or with the motor down, so there isn't extra heat from the hot water transferred into the motor. I also note some installers not fitting the tank & inlet sensors by the book either. I've seen two systems where the instaling plumber has drilled diagonaly through tank insulation & just pushed the sensor into the hole in the tank insulation.
One instalation had no insulation on any of the pipes.
Just reconfirms to me that standards of many fit the RAG definition (rough as guts), since apprentships became more paper theory, less practical & too plumbing firms use appretices as cheap labour with little or no oversight. The RAG jobs also typified by all the bits of instal scrap dropped on the ground all around the tanks. Responsibility for botht he instal deficiencies & lack of job pride has to rest squarely with the licenced bloke, not his apprentice.
Back on the insulation issue, I seem to remember some one posting in here once, information on purpose made moulded kits available for insulating the various fittings out of SHW tanks, but couldn't find it just now.
Posted Monday 10 May 2010 @ 12:36:55 pm from IP
# 
