G.A.S UK 4 Amp Pro Plus Hybrid Controller - Silent Step Control with Integrated Heater Output
Best for: growers who want quiet, click-free AC fan speed control plus coordinated heater switching from the same unit.
Our thoughts
The "Pro Plus" tag isn't just marketing here - it genuinely adds a heater control output on top of the Pro Step Controller's silent transformer-based speed steps. If you've used a cheap step controller before and hated the buzzing or the clicking between speeds, this is the fix. The heater coordination is the bit that makes it worth the "Plus" over the standard Pro version if you're running supplemental heat.
The G.A.S 4 Amp Pro Plus Hybrid Controller is a step-based AC fan speed controller built around a transformer with solid-state relays, giving five speed steps with silent, seamless transitions between them. Unlike cheaper step controllers, there's no audible clicking as it moves between speeds and no buzzing or humming from your fan even at low speed settings.
What makes it "Plus" over the standard Pro Step Controller is the addition of a heater control output that works in tandem with the fan speed control, helping keep your grow room close to a consistent temperature by coordinating both fan speed and supplemental heat rather than managing them separately. It's rated to handle 4 amps of fan load and is manufactured in Europe to a consistent build standard.
How it compares
The Pro Plus sits above G.A.S's standard Pro Step Controller and below full multi-socket environmental controllers like the Enviro4.
- Versus the standard G.A.S 4 Amp Pro Step Controller: the Pro Plus adds the integrated heater output; the standard Pro version is fan speed control only.
- Versus a basic rheostat-style speed controller: rheostat controllers often hum or click between settings; the Pro Plus's transformer-based steps are silent.
- Versus the G.A.S Enviro4: the Enviro4 controls four separate devices independently with day/night scheduling; the Pro Plus focuses specifically on fan speed plus heater coordination.
If you need silent step control and a heater working together rather than fighting each other, the Pro Plus covers exactly that gap.
Usage guidance
Setup is straightforward plug-in step control.
Fan speed
Select your desired step from the five available speeds - transitions between steps are silent, with no clicking or fan buzzing at lower settings.
Heater coordination
Connect your heater to the dedicated output so it works alongside the fan speed setting to hold your room closer to target temperature.
Fan compatibility
Use with AC fans rated within the controller's 4 amp handling capacity.
Technical specifications
- Control type: 5-step AC fan speed control with integrated heater output
- Manufacturer: Global Air Supplies (G.A.S UK), built in Europe
- Fan current rating: 4 amps
- Speed steps: 5, silent transitions via solid-state relays
- Technology: Transformer-based step control, no audible clicking or fan hum
- Additional output: Dedicated heater control channel
Who this is for
- Growers running an AC fan alongside a supplemental heater who want them working together
- Anyone who's been put off step controllers before by clicking or buzzing
- Growers wanting reliable manual step control rather than a fully automatic thermostatic system
Best suited to setups using a single AC fan up to 4 amps plus a heater, rather than multi-fan or EC installations.
Our take
This is professional-grade build quality applied to a genuinely useful combination - quiet step control plus heater coordination, without needing a full environmental controller to get it.
If noise and fan buzz have bothered you with cheaper controllers, this is worth picking up. Does exactly what it should, day in, day out.
