I bought a Helioakmi compact 200 solar heater. It’s properly installed but even with the electric element on it’s still not heating enough water for a few showers. In the evening the water is cold.

I am thinking of putting a circulation pump with two set of hot water pipes to keep the hot water circulation constant. Will it work?

  • How much water (gallons or liters) does the heater hold? – manassehkatz-Moving 2 Codidact Jan 7 at 18:10
  • 1
    From what I can tell from the manufacturer's information, this is only a water heater and it has no hot water storage. So it can be used for on-demand hot water during the day. If you are trying to use it for hot water during other parts of the day, you will need some sort of storage tank. I don't see how a circulation pump will help unless you have a place to store the hot water. – jwh20 Jan 7 at 18:51
  • You also haven't told us anything about your installation, climate, etc. There's not much we can say knowing so little. – isherwood Jan 7 at 19:03
  • "for a few showers", How many showers did it provide hot water for? How far far away are the shows from where your heater is installed? – Programmer66 Jan 7 at 19:39
  • Unclear on whether the issue is "first hot water delay" (owing to water in the pipes having cooled off) or a total runtime issue. This heater is supposedly 4000 watts, which is about 2/3 the capacity of a US style tanked water heater, so recovery time should be under an hour. – Harper - Reinstate Monica Jan 7 at 19:40

If it is properly installed and the auxiliary heater is working, you should have enough hot water for three or four hot showers. A 200 liter tank is approximately 52 US Gal which is the normal size for a family of 3-4 people.

Adding a circulation pump will not resolve the issue you are having. The circulation pump will shorten the time it takes for hot water to reach where your shower is located. It will provided a small amount of addition storage, but since your tank is ~52 gal, the additional storage in the pipes will be minimum.

Before adding a circulation pump, I would validate that the solar heater is working properly. At a daytime high temp of 24-25C degrees, the water is still cold and needs the electric element to bring the temp to about 52C (125 F) in order to feel like hot water is coming out of the shower.

I would check that the thermostat is set to at least 60C (140F), the factory setting. About 1 or 2 hrs before sunset, I would turn on the hot water and measure the water temperature.

If the water temp is 60C, then you know the thermostat and electric element is working.
If the water temp is not 60C, then you could have these potential problems:

  1. faulty thermostat
  2. Electric element not working
  3. Electric element is undersized

Do you have the standard 4000 Watt-230 v heater or did you select another heater option?

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