Worcester 24i boiler timer broken - can this be replaced by myself?

Can you replace the mechanical timer in a Worcester 24i junior with an electronic timer in the same location

Stew
September 2020

The Clock timer on the 24i pops out from the front. You dont need to remove the white metal front case, nor any other case... its done fro the gray panel at bottom.

There are three wires that connect at back of timer. make sure boiler power is turned off. make a note of where the wires go.. .disconnect, reconnect new timer.. .Bingo.. Not rocket science and no corgi or equiv engineer required.

Paul
February 2017

I've just found a range of different kinds of controllers that are compatible with Greenstar boilers, manufactured by Salus. I'll order one of those.
Graham.

Graham Beamson
November 2016

I just recently had an MT10 timer fail on my Greenstar combi boiler. It looked easy to replace so I sourced and ordered one from an internet supplier. It arrived quickly and I fitted the new timer without problems but it didn't work ! It had a different failure mode to the old one and I checked its operation using a test meter on the connector pins. It definitely wasn't working correctly. So I'll send it back to the supplier and ask for a replacement. Then again, maybe I'll source and fit a better type of timer switch.
Graham.
P.S. All the dire warnings on this forum about gas escaping round the cover are rather 'over the top'. There is no danger of that. You only need a small amount of common sense and replacing the timer switch is straightforward. It's a shame the replacement timer switches have a poor reputation.

Graham Beamson
November 2016

Yes you can replace yourself! Gas safe engineers are only human, not superheroes and if you watched them doing it you would see how easy it is after shelling out £100-150. Just don't mess about with any other stuff inside. Best option seems to be an electronic timer as mechanical ones are all made of chocolate clearly! Check youtube for a guide but don't go for the cheap mains timer option as advised by someone else as you won't get hot water when boiler is powered off

Stevie
July 2016

Shah74 you are a fool. The cover forms part of a seal. Advise like that can kill people. Don't comment on things you don't know about.

mj plumbing
May 2015

Gas safe plumbers are a ripoff the front cover has no seal arround it ,two screws at the top and two in plastic blocks under the bottom edge need to take the plastic panel from underside pull it to the front and take off one screw left of the clock which holds the lckink piece with an arrow on it and then lift the timer panel up and out unplug the four wire plug from the panel and fit new clock and put it all back as it was its simples.

sysh74
December 2014

Buy a programmable thermostat and leave the timer in the on position permanently.Amazon have a Salus priced at about £35 ,cheaper than a new timer and more controllable.

Frankiebodge
December 2014

...also don't bother replacing the mechanical timer with like for like - they are garbage. Spend an extra £20 and replace with the better digital D20 timer. Much better!

Jimbob
January 2013

You can DIY but the boiler casing is part of the main combustion chamber. If you need to ask on here I wouldn't take the risk! It involves removing the cover, part of the main circuit board and control panel at the front. Should only be done by a registered gas engineer. If you don't put the boiler casing on properly deadly gasses can escape. The cover isn't just for aesthics - its part of the combustion chamber and should be sealed and checked properly.

Jimbob
January 2013

these boilers' timers are rubbish
one workround is to set the pin on the on/off to permanently on then have a pound shop timer on the wall socket and set the time using that.
also as this makes it mains fired each time it gets over those annoying times when the boiler refuses to ignite and just idles,another fault with these boilers.

Ed
September 2012

To Replace the timer you must take the boiler casing off and this should only be carried out by a Gas Safe Registered engineer only.

Plum man
May 2010

did anyone manage to do this themselves? As I've got the same problem...

Mikie
March 2010

I am gonna replave the MT10rf, which I think is a real pain, with the simple MT10
The MT10RF has had the heating on all night last night even tho both stats were set to 5 degrees. Grrrr.

Ken
February 2010

hi everyone - hope you are all well. i discovered that my mechanical timer isn't working when i turned the heating on recently, and have been searching for a way to fix without shelling out for a plumber. i think i might have cracked it with a recent search that found this page on the worcester-bosch site:

http://www.worcester-bosch.co.uk/homeowner/literature/gas-boiler-literature/greenstar-28i-junior-literature

one of the pdfs in particular (http://www.worcester-bosch.co.uk/cache/file/14/mt10-instructions.pdf) looks like a pefect step-by-step guide to replacing a timer, so i'm going to have a crack at it! there seems to be a few places that you can source the timers from, and i'm probably going to try ebay first:

http://shop.ebay.co.uk/?_from=R40&_trksid=p3907.m38.l1313&_nkw=worcester+timer&_sacat=See-All-Categories

good luck!!

barry
October 2009

I have the same problem - but my timer falls out, spins round - and occasionally works - but is getting very annoying, there seems to be 2 types of timers - a mechanical one - part number 299 - 360 and an electronic one 299 - 361 - both the same price - but can vary greatly - I'm going to buy a timer and if I can't fit it - I'll get a plumber to do it - atleast I won't have to wait for a part

Susan
October 2009

no bother chicken - if someone helps us they'll have a twofer

Jo Mac
October 2009

I have a similar problem where as my clock goes round but does not engage the heating when set to.

I was also looking to see if the clock unit can be removed and replaced by myself.

Sorry for thread hijacking.

Noddy
October 2009