Short Cycling Copper Plumbing???

[bpirger]

So short cycling an oil boiler is a bad thing...letting it run for just a few minutes, off, then back on, etc. Bad for the burner, efficiency, etc.

How about changing the temperature of the water in one's primary loop a big amount frequently? I have the Garn plumbed as a secondary loop feeding into the primary loop. When the call for heat comes around, the water will increase in temp by about 50-60 degrees (or more) in about 20 seconds. Then the Tekmar controller will shut down the heat demand, and the primary will cool down, over a couple of minutes, and then the cycle repeats in about 10 minutes. So there is a big swing in the copper temp quite frequently during a cycle like this.

I also have the Buderus (G115) plumbed in the primary loop...so it too is seeing these swings in water temperature.

Any problems? Will the large number of repeated cycles cause any issues? What do you think?

 

[in hot water]

Unless you have long piping runs the thermal expansion should not be an issue. On long runs an expansion joint or expansion loop is often used to handle the piping movement.

It would be nice to eliminate or less the temperature swings, sometimes a variable speed circulator control can make temperatures smooth out. By changing the pump speed to the load or heat call you can save some electrical energy and lessen the wide temperature swings.

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