AutoDip Anti-Freeze Valve
Automatic drain valve for hydronic heat pump circuits — opens at around 3°C so the outdoor circuit cannot freeze in winter.
Specifications
| Parameter | Value |
|---|---|
| Series | AutoDip |
| Connection sizes | G1, 1-1/4", 1-1/2" |
| Working temperature range | 0–65°C |
| Maximum working pressure | 10 bar |
| Sensor element | Thermostatic element, no electrical supply required |
| Drain trigger | Approximately 3°C |
Values as published in the 2026 product catalogue. Ask us for the model-level submittal sheet before specifying.
Features
- ✓Automatically drains the circuit when the sensed temperature reaches about 3°C, preventing ice from forming in the system
- ✓Thermostatic operation — no power supply or control wiring needed at the valve
- ✓Three connection sizes covering the circuits used on residential hydronic heat pumps
Overview
The AutoDip valve is a thermostatic drain for the outdoor section of a hydronic heat pump circuit. When the sensed water temperature falls to around 3°C it opens automatically and drains the circuit, which is the point at which standing water starts to become an ice risk rather than a freeze risk. Because the element is thermostatic, the valve needs no power supply, no control wiring and no signal from the heat pump controller.
It is a small part that decides whether a winter service call is a reset or a replacement. Hydronic circuits that stay pressurised through a cold snap can split a coil, a pump housing or a fitting, and the damage is usually found in spring. Fitting a drain valve is the cheap side of that trade. It pairs naturally with the mixing centre and the filter on the same circuit.
Where it is used
- Outdoor hydronic circuits on air-to-water heat pumps in Canadian and northern US climates
- Seasonal or intermittently used buildings where the circuit may sit idle below freezing
- Retrofit protection on circuits that were installed without a drain point
- Service replacement where an existing drain valve has seized or lost its charge
Selection & installation notes
- 01
Size the valve to the circuit connection: three sizes are offered (G1, 1-1/4" and 1-1/2"), and the working range covers 0–65°C at up to 10 bar.
- 02
Confirm the drain point has somewhere to discharge to. A valve that opens correctly onto a frozen or blocked outlet has not solved the problem.
- 03
Mount it where the coldest water in the circuit actually collects — that is the temperature the element responds to, not the temperature in the plant room.
- 04
Because the valve is thermostatic, there is no commissioning step: verify the outlet is clear and leave it. Confirm per model on the submittal sheet if your circuit runs at an unusual pressure.
Common questions
Does it need power or a signal from the heat pump?
No. The element responds to temperature directly, so the valve operates with no electrical supply and no control connection.
At what temperature does it open?
The published trigger is approximately 3°C. The working temperature range of the valve is 0–65°C at a maximum working pressure of 10 bar.
What sizes are available?
G1, 1-1/4" and 1-1/2". Which one suits your circuit depends on the pipework at the drain point — confirming per model on the submittal sheet is the safe route.
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