A self-priming pump holds liquid inside — which can freeze in winter. Here’s how to protect a ZWL pump in cold weather so it primes when you need it.
| Flow Rate | 8–800m³/h |
|---|---|
| Head | 10–80m |
| Power | 1.5–75kW |
| Inlet / Outlet Diameter | DN25–DN300 |
| Material | Cast Iron, SS304, SS316L |
Not sure this pump fits your duty? Try the pump selector
Here’s a detail that catches people out in cold climates: a self-priming pump keeps a charge of liquid *inside* the pump body between runs — that’s how it re-primes. In freezing weather, that stored liquid can freeze, and a block of ice can crack the casing or stop the pump from starting. A little winter care keeps a ZWL direct-coupled self-priming sewage pump reliable through the cold.
The pump has a drain plug (bottom drain) at the base for exactly this reason. If the pump will sit idle in sub-zero conditions, drain the pump body through that plug so there’s no liquid left to freeze. Before the next start, refill it (at least two-thirds of the body) through the filling valve, and it primes as normal.
For a pump that must stay ready to run in winter, alternatives to draining are:
A frozen suction line won’t prime either — insulate or heat-trace exposed pipe. And remember the medium itself: if what you’re pumping can freeze or turn to slush in the pit, that’s a process issue to manage separately.
ZWL Direct-Coupled Self-Priming Sewage PumpWhen one pump isn’t enough or downtime isn’t an option, ZWL pumps run in parallel or duty/standby. Here’s how to set that up sensibly.
ZWL Direct-Coupled Self-Priming Sewage PumpWhich ZWL pump parts wear, and which spares to keep on the shelf? A practical guide to impeller, mechanical seal, sealing ring and bearings.
ZWL Direct-Coupled Self-Priming Sewage PumpThe mechanical seal is what keeps a ZWL pump from leaking — and what wears in abrasive or hot media. Here’s how to choose the right seal for your duty.
