No hot water unless tap is turned on full

[micpwelsh]

Hi my baxi 105e is going a bit weird the water only heats when the tap is turned on full , any ideas ?

 

[bab]

sounds like the dhw diaphram on way out. \It works on differential of pressure between hot outlet relative to cold mains feeding boiler. as they fail the diffrence required is greater. = more hot flow. to trip the micro switch.

 

[twgas]

diaphragm, possibly, or venturi. Had any parts recently?

 

[micpwelsh]

Had is serviced in march and gas guy changed the diaphragm then (said it was leaking or something)

 

[Agile]

You need to look at diverter valve pin when running hot water.

It should come out and operate the microswitch at about 2.5 litres per minute.

Tony

 

[twgas]

Then its probably the venturi

 

[micpwelsh]

2.5 litres a minute that's not much I'll check it out

 

[micpwelsh]

Pin coming out and pushing the switch at about a litre every 4 seconds

 

[gas112]

as twgas has said venturi if diaphragm is ok

 

[micpwelsh]

What's the venturi ? . I'm sure I could check the diaphragm as its not a gas part (will grahams sell a new diaphragm ? )

 

[picasso]

Pin coming out and pushing the switch at about a litre every 4 seconds

Thats 15 litres a minute, is the pin coming out at 2.5 litres per minute ?

 

[micpwelsh]

No

 

[twgas]

http://www.freeboilermanuals.com/pdf/baxi_disc/Combi-105HE.pdf

Page 28.

 

[micpwelsh]

Hi again changed the diaphragm , its wasn't broken but it was all stuck up with limescale type stuff . I gave it a good wash out and now it seems to be fixed thanks guys . should I be expecting that gunge to brake the boiler somewhere else ?