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Solar Hot Water Circulating Pumps
The circulating pump moves water between your roof collectors and the storage tank. It runs every sunny day for years, and when it seizes or loses its impeller the system stops collecting heat entirely — the booster quietly takes over and your power bill climbs.
We stock Grundfos and Wilo pumps for open and closed loop solar systems, drainback systems, and domestic hot water recirculation.
✔ Signs your pump has failed
- No hot water on sunny days, with the booster doing all the work
- Pump body cold and silent when the controller says it should be running
- Humming or buzzing without flow — a seized rotor
- Grinding, rattling or unusually loud operation
- Leaking from the pump head or unions
✔ Common replacements
- Grundfos 15-20 CIL 2 — the standard solar circulator, available with power lead fitted, with or without unions, in single, twin and Tradie Service Packs
- Wilo Star-Z NOVA — the current direct replacement for the discontinued Salmson SB 04-15, Salmson NSB 04-15 and Wilo Z 15A pumps used in Dux, Hills and Conergy systems. Available as a kit with a solar-rated non-return valve.
- Wilo Varios Pico-STG 15/1-7 — open and closed loop; replaces the Grundfos 15-65 and Viking pumps
- Wilo Solar-STG 15/11-1 — drainback systems
- Grundfos UPS range (20-60, 25-60, 25-80, 32-80) — light commercial circulators
- Grundfos Comfort 15-14B PM and Auto Adapt — domestic hot water recirculation
✔ Before you order
Check whether your existing pump includes unions and a power lead — some listings include them, some don't, and mismatched unions are the most common reason a pump swap stalls halfway. Our Tradie Kit bundles unions, non-return valve and flow meter.
✔ Why buy from us
- Current replacements for pumps that have been discontinued for years
- Pumps supplied with leads and unions fitted, ready to install
- Same-day dispatch before 3pm, free delivery over $150
✔ Replacing a discontinued pump?
Email sales@solarhotwaterparts.com.au with the model on the old pump and we'll confirm the current equivalent.
