This is the hub’s annual checklist, written as a homeowner’s guide. It is not a method statement and not a price. Roof work, pressurised glycol and unvented cylinders need a competent person. If the original install was MCS, use an MCS solar thermal installer for warranty-sensitive work.
Panels
- Visual inspection of the evacuated tubes or the flat-plate collector
- Visual inspection of the fixings
- Clean the collectors if they need it
How the two collector types sit on a roof is on solar thermal.
System
- Operate the air-removal devices
- Set pump speed and flow rate
- Check expansion-vessel pressure
- Check system pressure
- Operate the pressure-relief valves
- Check for leaks
Thermal fluid
- Check glycol (antifreeze) concentration
- Check glycol pH
- Replace the glycol when it is spent
If the glycol has to come out because the system has overheated (stagnation), the hub practice is to powerflush first, then refill. Heat-damaged fluid leaves residue; pouring new glycol on top of that is a short service. If the glycol is only old, drain and refill with new antifreeze.
Controller
- Check the controller settings
- Record hours-run
- Investigate if the system has overheated
- Explain the solar controls to the householder, including how to top up the store when the sun has not
A solar store can still feed a combi through an Intasol combi diverter valve. That does not remove the need to service the solar circuit.
Do not treat this as a DIY drain-down. Solar loops run hotter than a heating circuit, the fluid is not central-heating inhibitor, and a roof collector can stagnate at well above boiling if the pump is off on a clear day. Leave the glycol and the relief valves to someone who has done this plant before.
Related
Information is guidance only. Repairs and unvented or solar work need a qualified professional. Do your own due diligence; we accept no liability.