Henry Hoover High/Low Switch Not Working? Circuit Board Bypass
If you have an older Henry Hoover with a high/low power switch that has stopped working, the electronic circuit board can sometimes be the cause.
On these models, the high/low system can be removed so the vacuum operates as a simpler single-speed machine. The redundant high/low switch position can then be replaced with an LED power indicator, similar to the arrangement used on later Henry models.
This guide explains the basic process and the accompanying video shows the repair in more detail.
IMPORTANT: This repair involves mains-voltage electrical wiring. Disconnect the vacuum from the mains before opening it. If you are not competent working on mains electrical appliances, have the repair carried out by a qualified or competent person.
Before You Bypass The Henry Circuit Board
Don't assume the circuit board is faulty simply because your Henry has stopped working.
A loss of power can also be caused by the cable, rewind contacts, switch, motor or another electrical fault.
This repair is specifically intended for compatible Henry models fitted with the older high/low speed-control system.
If your Henry doesn't have a high/low switch, or you haven't diagnosed the fault yet, see my Henry power loss diagnosis guide first.
Watch The Henry Circuit Board Bypass
The video below shows the bypass and LED conversion on the Henry model being repaired.
What Does The Henry High/Low Circuit Board Do?
Older variable-speed Henry models use an electronic circuit board together with the high/low switch to control the motor speed.
If this system fails, the vacuum may stop working correctly even though the motor itself is still serviceable.
Bypassing the speed-control system converts the vacuum to straightforward single-speed operation. You lose the high/low function, so the machine operates at full power when switched on.
Step 1 – Open The Henry Motor Head
- Disconnect Henry completely from the mains.
- Turn the motor head over and remove the screws securing the casing.
- Carefully open the casing to expose the internal components.
- Locate the high/low circuit board and associated wiring.
Before disconnecting anything, take a clear photograph of the original wiring so you have a reference for your particular machine.
Step 2 – Remove The High/Low Circuit Board
On the machine shown in the video, the high/low circuit board and its associated switch wiring are removed from the circuit.
Once the speed-control system is removed, the motor can be wired for straightforward single-speed operation using the main on/off switch.
Do not rely on wire colour alone when carrying out mains wiring. Follow the wiring arrangement for your exact machine and make sure all connections are correctly identified and securely terminated.
What Happens After The Circuit Board Is Bypassed?
The high/low speed control is no longer used.
Instead, Henry operates as a single-speed vacuum:
- The main switch turns the vacuum on and off
- The motor runs at full power
- The original high/low function is removed
- The unused high/low switch position can be replaced with an LED power indicator
Replacing The High/Low Switch With An LED Power Light
Once the old high/low system has been removed, you're left with a redundant switch position in the casing.
A replacement Henry LED power light fits into this position and gives the conversion a much neater, factory-style finish.
It also provides a visible mains power indicator, similar to the light found on later Henry models.
Need The LED For Your Henry Bypass?
If you're removing the old high/low circuit board, this LED power indicator is designed to replace the redundant high/low switch and finish the conversion neatly.
How To Fit The Henry LED Power Indicator
The exact connections should follow the wiring arrangement shown for the compatible machine in the video.
- Remove the old high/low switch from its position in the casing.
- Fit the replacement LED unit into the vacant switch position.
- Use suitable wiring and correctly terminated connectors to connect the LED into the appropriate supply arrangement.
- Make sure every electrical connection is secure and properly insulated.
- Route the wiring so it cannot become trapped when the casing is reassembled.
Because this is a mains-voltage indicator, it must be connected correctly. If you are unsure about the wiring, do not guess.
Reassemble The Henry Motor Head
Before closing the casing:
- Check that all electrical connectors are fully seated
- Make sure there are no exposed conductors
- Check that no wires are trapped or positioned against moving parts
- Make sure the switch and LED are correctly seated
- Confirm that all removed components and loose wires have been dealt with correctly
Once everything has been checked, refit the casing and replace all the screws.
Testing The Repair
After a correctly completed bypass, the Henry should operate as a single-speed vacuum using the normal on/off switch.
The LED power indicator should illuminate according to its intended wiring arrangement, while the old high/low speed function will no longer operate.
If the vacuum still doesn't work after the bypass, stop and diagnose the fault rather than assuming another component should simply be bypassed.
Frequently Asked Questions
Why Has My High/Low Henry Hoover Stopped Working?
The speed-control circuit board can fail on some older high/low Henry models, but it isn't the only possible cause. The power cable, rewind contacts, switch, motor and associated wiring should also be considered.
Can You Bypass A Henry Hoover Circuit Board?
On compatible older high/low models, the speed-control system can be removed so the vacuum operates as a simpler single-speed machine. This is a mains electrical repair and should only be carried out by someone competent to do so safely.
Will Henry Still Have High And Low Power After The Bypass?
No. Bypassing the speed-control circuit removes the high/low function. The vacuum then operates at full power when switched on.
What Replaces The Henry High/Low Switch?
The unused switch position can be fitted with an LED power indicator, giving the repair a neat finish and providing a visible power light.
Do I Have To Fit The LED When Bypassing The Circuit Board?
The LED is part of the finished conversion shown here. It fills the redundant high/low switch position neatly while providing a useful power indicator.
Does The LED Make Henry Variable Speed Again?
No. The LED is only a power indicator. It doesn't restore the original high/low speed-control function.
What If My Henry Doesn't Have A High/Low Switch?
This particular bypass isn't intended as a general fix for every Henry with no power. If your machine is a standard single-speed model, diagnose the power fault before replacing or altering any components.
Giving An Older High/Low Henry A Simpler Setup
If the high/low circuit board has genuinely failed, converting a compatible machine to single-speed operation can keep an otherwise serviceable Henry working.
The LED power indicator then fills the old high/low switch position and gives the finished repair a much neater appearance.