Rinnai N Series external continuous flow water heaters use an anti-frost protection system to keep internal components from freezing in cold conditions — electrically powered heating elements that activate automatically as temperature drops, protecting the appliance down to -20°C. It's what allows an external unit to keep working reliably through harsh winter conditions rather than seizing up the first cold snap.
If this anti-frost heater fails, that protection is gone, and a hard freeze can put the appliance out of action with a repair bill well beyond the cost of the part itself. The PN-721 is the genuine Rinnai replacement for the N Series, made to the original specification, restoring frost protection and letting the appliance run as intended through the coldest part of the year.
⚠ Important: This part should be fitted by a suitably qualified engineer.
An external water heater without working frost protection is one hard freeze away from a much bigger repair bill. This genuine part restores the anti-frost system to its original -20°C protection rating, so the appliance keeps running through winter instead of becoming a cold-weather casualty.
Order the Rinnai PN-721 N Series Anti Frost Heater online today.
| Manufacturer | Rinnai |
|---|---|
| Part Number | PN-721 |
| Product Type | Anti Frost Heater |
| Compatible Series | Rinnai N Series (External Models) |
| Function | Provides Frost Protection for Internal Components |
| Protection Rating | Down to -20°C |
| Application | Continuous Flow Gas Water Heater |
| Installation Requirement | Qualified Engineer Recommended |
