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Supply Manifold

Return Manifold

Return Manifold

The liberal use of threaded unions allows for easy removal of components for repair or replacement.

Fortunately, I had installed unions around the pump with serviceability in mind, so I simply closed some valves and removed the section. I unscrewed the fittings on each side of the pump, reversed it, and reinstalled it. The moment the pump began to run, I watched the incoming temperature gauge rise to over 220°F (104°C) from the stagnant hot water in the collectors. In a few minutes, it settled down to a nominal 155°F (68°C), which seemed to be the system's normal capacity (more on that later).

I wholeheartedly recommend that all systems have a liberal sprinkling of unions to allow for service disassembly. I also found some leaks around my heat exchanger, and rectified that by removing the whole assembly and tightening the fittings.

PV & Collector Problems

In the first few days of full sun, I noticed that the pump didn't kick in until after 10:30 AM. I first thought that the solar-electric panel that runs the circulation pump was underpowered. On the third sunny morning, I went out and looked at the PV panel. I saw that I had mounted it up slope from the air vent I had installed on a 6 inch (15 cm) extension above the collectors, and the air vent was shadowing the PV! So I moved it over by a foot and fixed that silly mistake!

When I mentioned to Naoto that my operating temperature was a nominal 155°F (68°C), he was surprised, since the design spec is closer to 180°F (82°C). He had been having trouble with other SunEarth Empire series units underperforming, and contacted the factory.

The SunEarth engineers were very responsive and soon learned that there was a manufacturing defect in the units. They arranged with Solar Market to replace

The air vent shaded the PV panels in the early morning, causing a delay in pump operation—Oops!

those units that were already installed. The first set of replacements I received was not packed properly and the panels were badly damaged in shipping. Almost four months later, I finally have the new units, and must now wait for a warm, dry day! Right now it's inches of mud and raining hard, with snow in the forecast! Check my Web site for details on the new panels and their performance.

Underpowered Floor Circulating Pumps

The next setback came when the propane supplier came to hook up the AquaStar heater. We couldn't get the heater to kick in, even though the circulating pump was running. I realized that mine is a closed system, and the AquaStar relies on a pressure difference of 10 psi to turn on.

This is fine in an open system. When you turn on a faucet, the outfeed pressure drops, turning the heater burner on to the degree needed to bring the water flowing through it to temperature. It looked like the pump (Taco 003 series) was underpowered. This was very distressing!

I called Naoto at Solar Market and he immediately drove over (a trip of more than an hour!) in his biodiesel

Marsden Heating System Costs

Item

Cost (US$)

2 SunEarth Empire series 4 x 8 foot collectors

Renewable Energy Eco Friendly

Renewable Energy Eco Friendly

Renewable energy is energy that is generated from sunlight, rain, tides, geothermal heat and wind. These sources are naturally and constantly replenished, which is why they are deemed as renewable.

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