Repair of a swimming pool solar heating system

Our latest swimming pool heating system project involved a system that was installed a number of years ago and was working rather inefficiently. We agreed to undertake a full evaluation of the system first before proposing major upgrades to the system. The system was documented by the installer but we couldn’t be sure about the accuracy of the documentation as several repairs and adjustments had been made over the years.

Evaluation of the current system

As a first step, we inspected the whole system on one of the hottest days of the year so far which posed a number of challenges. The system comprises of 2 arrays of solar thermal panels, totalling 22 in total. Whilst one of the arrays appeared to be working, the other had at least 1 leak due to solder connections weakened by overheating. A previous installer left a mains refilling loop open which meant that fresh water was pouring out of the leaking joint. We further checked the following

  • system pressure
  • Automatic Air valves
  • Flow directions of both systems
  • expansion vessel conditions
  • flow gauge conditions
  • solar controller settings
  • heat exchange efficiency

Evaluation results

Beyond the obvious leak on the system, we also established that the pump for one of the arrays was no longer working. The constant flow of water had cooled the panels even it the very hot water but no circulation meant that the panels were not contributing to heating the pool.

We also noticed that the heat exchanger for the pool water was getting too hot, indicating poor efficiency.

System repair

After discussing our finding with the client we ordered and installed a new high efficiency solar pump to replace the broken one. We fixed the leak on the solder joint and stopped the constant flow of water through the system. With both arrays now working, we set about improving the efficiency of the swimming pool heat exchanger.

Since our repair, the system has been running reliable with a significant improvement in lifting the swimming pool temperature through both solar panel arrays.