Frequently Asked Questions

How does a Warpfive Stove Fan work?

Warpfive Stove Fans are miniature Stirling engines.  They work by moving a sealed volume of air from the hot bottom plate to the cool top plate of the engine. As the air moves from the cool plate to the hot plate it is rapidly heated, it expands and pushes the piston up. As the air is moved from the hot plate to the cool plate it cools rapidly and contracts, this creates a vacuum which pulls the piston down. This same volume of air is rapidly heated and cooled many times per second. As the piston is connected to a crank shaft it causes the crank to rotate and this produces the mechanical power to rotate the propellor. For additional information, click here to view our animated graphic.

Which Warpfive Stove Fan do I need?

This comparison chart will make choosing a stove fan easy.

What is the first step when choosing a stove fan?

You need to establish the temperature of your stove surface which can easily be done with a Warpfive Stove Top Thermometer.  If you don't have an accurate thermometer, place a drop of water on the surface - if it bubbles away instantly, you'll know your surface is above 100 C (212 F).  The heat on your stove surface powers the engine which provides the energy to spin the propeller.   

I have limited space above my stove – which stove fan do I need?

The Warpfive Sidewinder Stove Fan is specifically designed to fit into most restricted spaces.  Its overall height is 225 mm (including the propeller)

I have a very large room - which stove fan do I need?

The Warpfive Twinspeed Stove Fan is premium high performance engine with twin piston cylinders.  This makes it exceptionally powerful and able to move large volumes of air (in excess of 440 CFM), the perfect choice for a large room.

How reliable are Stirling engines?

Stirling engines are incredibly reliable as they have no electrical components which can burn out.  Our test engines have exceeded 21 864 continuous hours and are still running ... this is equivalent to 14.9 years of non-stop use! 

How do I maintain my Warpfive Stove Fan?

Like any engine a Stirling engine requires basic care once every season or after approximately 1000 hours of use.  This entails wiping clean and lubricating the displacer shaft with the supplied lubricant.  Please see user guidelines for more information.  

Can I use any oil to lubricate my Warpfive Stove Fan?

It is important to use our supplied lubricant only because it is a synthetic, high temperature oil specially developed for use in extreme heat environments.  Using other oils such as mineral oil or light machine oil, will result in a sticky residue which will damage your engine’s performance.

My engine is making a squeaking sound?

It is likely that the squeaking is a result of the propeller hub touching the vertical upright.  Loosen the grub screw on the propeller hub and withdraw the propeller by 1 mm.  If the squeaking persists, hold the propeller by the hub and move the entire shaft back and forth, returning it to a central position.

How do I use my new Warpfive Stove Fan?

Place the engine on top of your stove and allow a couple of minutes for the base to heat up.  Different engines have different operating temperatures.  Once the base of the engine has heated up sufficiently, gently spin the fan blades.  The fan will slowly start to rotate and gain speed.  The higher the temperature of the stove, the faster the fan will spin.  If the propeller does not spin, it is because your stove top is too cool. 

Can I use the dust cover while my engine is working on the stove?

Yes you can so long as you spin the propeller as soon as it reaches operating temperature to keep the dust cover cool - it must not exceed 90°C (194°F).  Place the engine at least 150 mm (6 inches) away from the flue, however for hot fires in excess of 250°C (482°F), place the engine at least 200 mm (7.9 inches) away from the flue.

Will a Stirling engine work on a pellet stove?

Yes a Stirling engine will work on any surface so long as there is sufficient heat transfer into the base of the engine.  All of our stove fans have minimum start up temperatures.  If the base of the engine reaches this minimum start up temperature it will work.  

Do Warpfive Stove Fans make a noise when they're working?

Operation is quiet - typically 36dB.  We use precision bearings and glass piston cylinders to ensure the engine will work quietly.

I can’t feel any air movement?

The higher the temperature of your stove surface, the faster your fan will spin.  When the room temperature is the same temperature as the air being moved by the propeller, it can be difficult to ascertain any movement.  Wet the back of your hand with cold water and hold it in front of the propeller – this will instantly give you some indication of air movement.  Warpfive propeller blades have been optimised to move maximum air at low RPM.

I live outside of the United Kingdom.  How long will it take for me to receive my Warpfive Stove Fan?

 UPS is our carrier of choice and most shipments outside of the UK take between 5 to 7 days to be delivered.

How do I book a service for my engine?

Please return your engine to Warpfive, remembering to include your name and contact details. It is not necessary to return your propeller.

How much does a service cost?

Please contact us for pricing.

What does a service include?

A service includes cleaning, re-lubrication and the replacement of any worn parts.

If your question is not covered here, please contact us - we will get back to you as quickly as we can.