Honeywell40003916-001 V4043 Replacement Powerhead Zone Valves, 240 V

when you need one of these you need it quickly; this was delivered the day after I ordered it, better than going to the local plumbers merchant, and despite delivery it was still cheaper. These are easy enough to fit, they don't last forever and its a nuisance when they fail. Care is needed in re-fitting the coloured wires to the control system so do them one by one or you will get into a hopeless muddle.

Does what it says on the tin.Easy job to replace (just be sure to check the power is definitely off) - just swap wires like for like. You may end up with a spare wire on some installations which the instructions just tell you to isolate.Anyway, has been installed for a couple of weeks and is working great - saved myself a packet on the quote from a plumber and job was done in 20 minutes.

Works fine and easy to fit as DIY job - a replacement for an existing one, which lasted about 20 years.

A little pricy for what it actually is but easy to install with a quick look through the leaflet

good quality product

A simple fix to what would otherwise be an expensive plumber/electrician callout. I have 3 of these Honeywell valves in my Central Heating/Hot Water system. The powerhead on each valve independently failed after about 8 years, either because the internal motor stopped working or the metal gear mechanism linking the motor to the final drive bent out of shape. The hardest DIY part is spotting that it is the valve causing the problem to begin with..... the powerhead may make a funny buzzing sound for a week or so before it gives up (which is a big clue), or the central heating or hot water may not heat up, or electrical water pumps may not run since there is an electrical link between powerhead and pump. To check if the powerhead is to blame, see if the metal manual lever (visible below the flex) is set closed/left or open/right. The lever always rests in the left position, even when the valve is open, so you have to move it gently across with your finger until you feel resistance. You can latch the lever on the right (as in the photo) to set the valve open if it is not there already, or leave it unlatched and see if it moves left and right as the valve closes and opens according to the demands of your heating thermostat. By the way, no plumbing or water draining is needed to change the powerhead, the old one simply unscrews off the valve body and you then put this new one on.

The Honeywell valve I originally had fitted since 2005 and so lasted for 13 years. On that basis I decided to replace it with exactly the same again. Hot water now working again and so easy to fit. Just remember to either take a photo of the connections or make a written not if there are a few wires blocking the view. The white wire seemed to be redundant in my case and so I followed the instructions and isolated it on a spare terminal.

These powerheads have a finite life. I had the same problem as Jon (June 2016). The microswitch was not closing intermittently due either to a motor malfunction or the gear mechanism being worn, or both. This caused the CH to close down. Intermittent faults take time to pin down and I first thought it was a Siemens controller fault.Changing it was straightforward. Just keep a note of the existing wiring before you take out the faulty powerhead.