I have a combination boiler and just recently the hot water doesn't always come on when I turn the hot tap on, if I fiddle with the hot water knob on the front of the boiler it will usually come on, but it is driving me mad, before I call a plumber out is this something simple or not?

cheers

 

for Matt.

I wish I could help, although we fitted our own Combi, I don't really understand enough about how they work to diagnose this.

Maybe its something to do with Mains Pressure? Does the boiler need to see a certain pressure before it heats the water? Just a thought.

Come on Tiff!!

 

sounds very similar to a problem i just had with my boiler, don't know what it was but it cost me Ł200 to fix

Sorry mate

 

thanks guys Ł200.00, I really hope not

 

When you say "come on" you mean flow from tap? ... or flows but doesn't heat up?
Sounds like a flow switch ... That 200 is OTT!
Possibly scaled up. sometimes is possible to descale, clean and reassemble with a service kit.

Get all the details of the boiler and the Gas number from the plate in it.

 

thanks mate , sorry I did mean that it doesn't always get hot, it is intermittent , I will get the details of the boiler, I have the manual if that helps

 

I had a combi-condensing boiler which did the same as yours. All I could put it down to was if the pressure in the heating system dropped which it did due to a leaky rad then the boiler would not switch on when the hot tap was opened. Check the pressure in the heating system, you should have a pressure guage on the boiler somewhere. There should also be a means of topping up the heating system quite easily.

 

right boiler make and model whould help but 99 % shure it will be the diverter valve. its a big washer that goes up and down every time you open a hot tap and in the end it splits and stops moving under pressure which in turn stops pushing a pin up on to a micro swithch which tells the boiler to fire up.
If its just a washer needed these cost about Ł2 to Ł3 if you can get just the washer for your boiler as some you have to buy the hole valve which cost about Ł100 + then you just need to get it fitted.
hope this helps dunc

 

Thanks guys much appreciated, the model is Halstead Finest Gold
Thats all I can find

thanks for any further help anyone can be

 

good god!! not the boiler you want!

well the only knobs on the front are the thermostats for heating and water so they ant going to help getting the boiler working.

there could be a loose connection on the pcb as this is directly behind the knobs you are talking about. wouldnt advise going in there unless you know what you are doing?

as said by others, it could be the diverter valve but by moving thermostats on the outside of the boiler it will not fire up - so doubt it is this.


best bet so far would be the loose connection on the pcb

 

Arrrgghhh a Wickes special. These eat boards like its going out of fashion. If you live in a hard water area it could be the diverter scaling up so it doesn't move plus if not used for more than a fortnight or so they are prone to sticking.

 

Any ideas on costs guys,best and worst case scenario's

 

Dont buy spares through Wickes deal direct with Halstead. If you are getting a plumber its Ł60 min with callout to Ł150 max. Ask for old parts that have been replaced and dont let anyone tell you they are exchange.

 

Thanks Cam, dont want my pants pulled down well not by the plumber anyway

 

before you buy a PCB just make sure all the plugs are on the board snugly


LOL - someone else who loves halsteads!

 

a new pcb for a baxi boiler is Ł75 so i would imagine it will be roughly the same. from my experience wid combi boilers i would say its fubarred get a new one and be done wid it, it will be cheaper in the long run. i used to find my combi boiler was always temprementle when the climate changed, summer to winter or vice versa. something to do with build up on the filters or summet, just a thought as the last week it has become noticeably colder, well it has in the lake district anyway.

 

pcb's for Halsteads are 120-140 quid .. last time I did one 4 years ago.

Diverter/Flow switch is worth looking at after several years of service

 

MANY THANKS GUYS
Any of you in Hants?

 

No .. .Thanks goodness!

 

last time i had a problem with my boiler i was taken to a showroom and had to buy another one, i can still feel the pain i went through when i had 1800 quid relived from my poor dads bank account ( will be mine when he snufs it though )

not olny was mine too small comparewd the the original he charged me for the bricks for the hole he left, the wiring and fook knows what else


and the fooking think never worked after he left

turned out the gas meter was letting too much gas through making the boilers autoshut off and so never allowed the boiler to light, a saftey measure


sorry i cant help but boilers are a nightmare, just hope this one lasts as long as the other one

 

if he is making the boiler come on by turning a knob on the front it aint gonna be the diapraghm thats persished

 

Dont know why you are quoting me .. I said that, and asked what he meant by "not coming on" !

 

What pressure should be showing on the little gauge thing it currently shows about 1 bar

 

yes thats fine

next time it fails to come on - try pushing the panel where the knobs are instead of turning the knobs (if that doesnt work try turning the knob like you did before)

still playing up i take it?

 

Yep, -pushing the panel deffo works , the boiler works most of the time but every so often it needs a quick push

 

Soldering-iron time!

 

before you blow the board up just make sure that all the plugs are tight on the pins

then do what al bags said and get searching for dry joints on the back of the PCB



YOU OWE ME Ł30 BY THE WAY

 

sounds about right ,nice one mate