You’d like to imagine that once your solar water system was installed you would not have to do anything except count the extra money you have saved. But generally what we tend to find is the higher the efficiency and performance of your solar hot water system the higher the service bill can be if you don’t perform basic maintenance. If you spend $5000 on a motor vehicle you normally will have it serviced many times within the first few years of owning it. Solar hot water systems should not be any different. Systems tend to start breaking down around the 4 to 5 year mark and some people do not even know they have stopped working.
By not having to use electricity or gas to heat hot water can cut the average household energy consumption bill by more than 35%.
But in the big picture your savings can be massively eroded by the maintenance costs.
That is not what you want to hear. However it is far better to know this now rather than later. Which is why you need to understand this while buying a solar hot water system.
In essence there are three types of solar hot water systems-
- The split flat panel is also known as an active system because it requires a circulating pump and an electronic controller/sensor to activate the pump to move solar heated water from the collectors positioned on the roof to the storage cylinder at ground level. These systems are efficient but have more moving parts that can need replacing.
- The split evacuated tube collectors is also known as an active system because it requires a circulating pump and an electronic controller/sensor to activate the pump to move solar heated water from the collectors positioned on the roof to the storage cylinder at ground level. These systems are extremely efficient but have more moving parts that can need replacing.
- Roof mounted systems are also known as a passive system because it does not need a circulating pump etc. Sometimes it is referred to a high line solar system as the tank is on the roof. Or as an integrated system/compact system because the solar collectors and the tank are close coupled. It is a very simple hot water system because water in the collectors rises as it is heated and is then stored in the tank. The process of heated water rising is known as Thermosyihoning. They are efficient in the correct location and use but no where as efficient as an evacuated tube solar hot water system.
Here is a quick low down on the maintenance requirements for the first two types of systems.
The Split System periodically needs these items replaced:
- Circulating pump – $220 – $350 +
- Electronic controller – $250 – $350 +
- Roof and tank sensors $35 – $80 +
- Air remittance valve $80 +
- Frost protection valves – required if they’re not evacuated tube solar collectors and in a frost zone. Frost valves are $180 each and each flat plate glass collector panel requires one. They require replacement every 2 – 5 years depending on water quality.
- Pressure and temperature relief valve $150 + Replacement is every 2 – 5 years depending on water quality
- Sacrificial anode – replacement every 2 – 5 years
- Cold water and hot water expansion valve $80 replacement every 2 – 5 years
The Roof Mounted system-
- Frost protection valves – required if the solar collectors are flat plate glass collectors unless glycol (anti-freeze) is not being used in cold climates where frost damage can occur
- Pressure and temperature relief valve
- Cold water and hot water expansion valve $80 replacement every 2 – 5 years
- Sacrificial Anode – replacement every 2 – 5 years
As you can see the Roof Mounted system is a lot less complicated but not as efficient either.
Something important to know and is often overlooked with a split system is the fact that if there is a power outage/blackout the split system will not produce hot water for a period of time. It does not matter that it is a clear sunny day because if there is no electricity to activate the circulating pump heated water can not be moved from the collectors on the roof to the storage tank on the ground. This can lead to stagnation causing an air lock in the system and damaging the collector sensor and circulation pump.
