Solar Water Heater Repair Dubai
A solar water heater almost never stops giving you hot water. It stops giving you free hot water, and the electric backup quietly takes over. That is why most faults on these systems run for months before anybody notices.
The signal is a bill rather than a cold shower. If your electricity has crept up and nothing else changed, the solar side is the first thing worth testing.
We work on the collectors, the circulation, the controller and sensors, and the backup element. If what you have is a tank with an element and no panels, the water heater repair page is the right one.
Signs the solar side has stopped
- The electricity bill rose with no change in habits.
- Hot water is fine in the evening but poor first thing.
- The tank is hot at night and cold after a sunny day.
- The controller display is blank, frozen or showing a sensor error.
Any one of these means the backup element is doing work the collectors should be doing. The hot water never stopped, which is exactly why it went unnoticed.
What a solar system is made of
Six parts, and five of them are nowhere near a bathroom. This is why a plumber who only works on tanks often cannot find the fault.
- The collectors
- Flat panels or rows of glass tubes on the roof. They fail by losing output rather than by breaking: dust on the glass, a tube that has lost its vacuum, or an absorber plate that has delaminated. All of it is gradual.
- The circulation path
- How heat gets from the roof to the tank. Either it rises on its own, which needs the tank above the collectors, or a small pump moves it. A failed pump stops the system dead while the hot water keeps arriving.
- The controller
- A box that compares collector temperature with tank temperature and runs the pump when it is worth running. When it fails the pump either never runs or runs all night, cooling your tank through the roof.
- The sensors
- Two or three probes feeding the controller. A sensor that has drifted or failed is the most common fault on a pumped system, and it is a cheap part that makes an expensive system behave as if it is dead.
- The backup element
- An ordinary immersion element in the tank for cloudy days and heavy use. It is the reason you still have hot water, and it is also the thing running up the bill when the solar side has quit.
- Roof pipework and insulation
- Insulation on a flat roof here takes a beating and it perishes. Bare pipe between the collectors and the tank throws away a useful share of what the panels collected, invisibly.
What the system is doing, and what it points at
Solar faults show up as patterns through the day rather than as a single symptom, which is the main thing that makes them different to diagnose.
Hot at night, cold in the morning
The backup element heated the tank overnight on cheap hours and the collectors added nothing all day. The solar side is not contributing at all.
Pump, controller or sensor
The tank cools on a clear day
Circulation is running when it should not be, so heat is being carried up to the roof and lost there. Reverse circulation, almost always a controller or a sensor reading wrong.
Controller logic or a failed probe
Output has faded over years
No single failure. Dust film on the glass, perished insulation and scale in the tank, all adding up. Usually recoverable without replacing anything.
Cleaning and insulation
Some tubes warm, some cold
On an evacuated tube collector, individual tubes lose their vacuum and stop working while their neighbours carry on. They are replaced singly rather than as an array.
Failed tubes
The controller shows an error
Usually a sensor open circuit, which the controller cannot tell from an impossible temperature. The sensor and its cable run across a roof, so the cable is as likely as the probe.
Sensor or its wiring
No hot water at all
The one case where solar is probably not the subject. If the backup element has also failed you lose hot water completely, and that is an ordinary element fault in an unusual tank.
Backup element
The element side of that last one works exactly as it does in any tank, and it is covered on electric water heater repair.
The solar side, or the tank side
A solar installation is two systems joined at a tank. Knowing which half has the fault decides whether anybody needs to go on the roof.
The solar side
- Hot water is fine but the bill has climbed
- The tank gains nothing on a sunny day
- The controller is blank or erroring
- The pump is silent when the sun is full on the panels
- Pipe insulation on the roof has crumbled
- Some collector tubes are cold to the touch
Collectors, circulation, controller or sensors. Roof work, and the half of the system most contractors are not set up for.
The tank side
- No hot water at all, day or night
- The breaker trips when the backup runs
- Water from the tank runs brown
- Rumbling from the tank
- A leak from the cylinder or its fittings
- Hot water runs out and recovers slowly
An ordinary tank fault that happens to be fed by panels. Element, thermostat, scale or the cylinder itself, as on any water heater.
How we diagnose it
- 1
Read the controller
Collector and tank temperatures, pump state and any logged error. Two numbers on a sunny afternoon tell you most of what you need to know.
- 2
Prove the sensors
Each probe measured and compared against an actual temperature. A controller acting irrationally is usually being told something untrue.
- 3
Check the roof
Glass condition, individual tubes, insulation, the pump and the expansion side. This is where the faults nobody has looked at for years are found.
- 4
Then test the tank
Backup element, thermostat and cutout, and the state of the scale. Done last, because the tank is the half that is usually fine.
Roof access in a villa is straightforward. In a building it needs arranging with the facilities team, so tell us the address when you book.
What usually turns out to be wrong
In our experience the expensive parts are rarely the problem. Collectors have no moving parts and they last. Tanks are tanks.
What fails is the small stuff: a sensor, a pump, a controller, a length of perished insulation. Those are the parts nobody inspects, because the system kept delivering hot water the whole time and gave no reason to look.
So the first visit on a solar system that has been ignored for years is usually a cheaper conversation than people are braced for. The money that has already gone is the money the backup element spent while nobody knew, and that part cannot be recovered. Stopping it can.
If the system is sound and simply dirty, that is a solar water heater cleaning visit rather than a repair, and it is the cheapest useful thing you can do to one.
The rest of what we look after
Solar work sits across two of our trades, so the tank and pipework are plumbing and the controller, pump and backup supply are electrical. The ordinary tank side is water heater repair, the annual flush is maintenance, a new system is solar installation and a dusty one is cleaning. We also cover handyman work, painting, carpentry, tiling, renovation, gypsum partitions, false ceilings and air conditioning, with the full list in one place and an AMC covering the lot on one schedule.
Where we work on solar systems
Villa communities mostly, since that is where the roofs are, but towers with roof mounted systems too. If your community is not listed, ask us.
New Dubai
- Dubai Marina
- Jumeirah Lakes Towers
- Palm Jumeirah
- Jumeirah Beach Residence
- Emirates Hills
- The Greens and The Views
- Discovery Gardens
- Dubai Media City
Central Dubai
- Downtown Dubai
- Business Bay
- DIFC
- Al Barsha
- Jumeirah
- Umm Suqeim
- Al Quoz
- Trade Centre
Old Dubai
- Deira
- Bur Dubai
- Al Karama
- Al Nahda
- Mirdif
- Al Qusais
- Oud Metha
- Garhoud
Outer communities
- Arabian Ranches
- Jumeirah Village Circle
- Dubai Silicon Oasis
- Dubai Sports City
- Damac Hills
- Motor City
- Dubai Hills Estate
- International City
Solar water heater questions
How do I know my solar water heater has stopped working?
You usually do not, which is the problem. The backup element covers for it so the hot water never stops, and the only signal is the electricity bill rising for no apparent reason. The practical test is to compare the tank temperature in the early evening after a clear day with the temperature first thing in the morning. If a full day of sun added nothing, the solar side is not working.
Why is my tank hot at night and cold during the day?
Because the backup element is heating it overnight and the collectors are adding nothing. That pattern is almost definitive. The cause is on the circulation side, which means the pump, the controller or one of the sensors feeding it, and all three are inexpensive compared with what the element has been quietly spending.
Can individual solar tubes be replaced?
Yes, on an evacuated tube collector. Tubes lose their vacuum one at a time and a dead tube simply stops contributing while its neighbours keep working. They are replaced singly, which is why a collector with a few cold tubes is a small job rather than a new array.
Is it worth repairing an old solar system or should I remove it?
Nearly always worth repairing. The parts that last are the expensive ones, the collectors and the tank, and the parts that fail are the cheap ones. Taking a working collector array off a roof and reverting to an electric heater means paying to install the thing that was already costing you money.
Do you need roof access?
For most faults, yes. Five of the six components are on the roof, and a diagnosis done only at the tank can confirm the tank is fine without ever finding the fault. In a villa this is straightforward. In a building it needs arranging with the facilities team in advance, so tell us the address when you book.
Does hard water affect a solar system too?
Yes, in the tank, exactly as it does in any other water heater. Scale settles on the bottom and on the backup element and reduces both the capacity and the element life. On top of that, dust on the collector glass reduces what the panels gather, so a solar system has two things to keep clean rather than one.
Book solar water heater repair
Tell us whether the hot water has actually stopped or only the bill has moved. Those are two different visits and the second one is the common case.