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Replacement Roof Sensors for Solar Hot Water Systems
The roof sensor sits at your solar collector and tells the controller how hot the panel is. It's the hardest-working part of the system and the most exposed — decades of UV, heat cycling and weather make it the single most common solar hot water failure we see.
✔ Signs your roof sensor has failed
- Pump won't start even on a hot, sunny day
- Pump runs at night or in cold weather
- Controller reads an impossible roof temperature (very high, very low, or dashes)
- Sensor fault or open-circuit error on the controller display
- Visible damage to the lead — cracking, rodent damage, UV perishing
✔ Choosing the right roof sensor
Three things must match:
- Lead length — 2.5m sensors join to existing cabling at the roof; 15m and 20m sensors run the whole way back to the controller. Measure or match what's already there.
- Plug type — Aestiva and Senztek have both old-style and new-style plugs. They are not interchangeable. Photograph your existing plug before ordering.
- System or controller brand — we list sensors to suit Solahart and Rheem Lo Line, Chromagen, Hills Solar Esteem and Esteem II, Hills Apollo Exceed, Dux, Rinnai Sunmaster, Apricus, Thermann, AAE, Edson, SolarArk, Zen Solar, Endless Solar, Aims, plus RESOL and Senztek controller ranges.
✔ Why buy from us
- One of the widest roof sensor ranges in Australia, including obsolete systems
- Free thermal heat paste with most sensors — essential for accurate readings
- Same-day dispatch before 3pm, free delivery over $150
- We'll identify the sensor for you if the system is unbranded or the labels are gone
✔ Can't identify it?
Email sales@solarhotwaterparts.com.au with a photo of the plug and the controller, and we'll tell you which sensor fits.
