vocera linea 02 lockout

[arundel gas services]

i have a 2 year old linea that lock out on 02 about every 2 to 3 weeks it is the one with the water pressure s/w i have tryed changing ,pump,thermistors,o/h stat both display and main pcb and water flow s/w there is a bypass and all the tempratures seem correct at the time i visit this is an obscure fault i am not a dummy has anyone else had anything simmilar ????

 

[Agile]

I assume from your name that this is not at your home but at a customers home.

From what you have changed it sounds as if you come into the category of a "parts changer".

Unfortunately I cannot remember all the fault codes for the whole range of boilers but assume as you changed the pump that its a low system flow code. However the boiler does not have any flow transducer. It is therefore necessary to consider what information the PCB can actually gather to make its assumptions.

Tony

 

[arundel gas services]

02 fault code is overheat lockout

 

[Agile]

Have you checked the max/min/ignition gas pressures and the DHW performance to see if the DHW HE is blocked ?

Tony

 

[arundel gas services]

no i am not a parts changer if i get it wrong i stand the cost of parts all these parts were recomended changing by voceras help line i have never failed to repair A LINEA BUT THIS ONE is pushing me to the limit
if i was a parts changer i would have gone bust a long time ago

 

[arundel gas services]

yes all pressures are correct and h/exc is clear also water in system is spotless proved by color of pump impellor when changed

 

[scatmanjohn]

Code 02= overheat.

Is there trv's on all rads?

How far away from the boiler is the bypass?.

 

[arundel gas services]

about 15 ft i think the on board diagnostics are lying to me

 

[Agile]

You keep mentioning a "Vocera" !

The only boiler manufacturer with a Linea 24 that I know of is "Vokera" ???

 

[Slugbabydotcom]

Integral by-pass could be blocked

 

[coltmanneil]

I have a vokera linea 24 and have had it for 6 years with a catelogue of problems.Including expansion tank,diverter valve seal going twice and the motor that sits onto of this valve going 3 times.Inline sensor once.

My latest intermittant problem is -The boiler comes on timer 6 oclock for heating and water,then we use the shower about an hour later.When using the shower the hot water(ie boiler just stopped heating the water).
There was no fault codes and the lights etc on the panel were still on.It was as though it had reached temperature and turned itself off.I immediately turn the button to off reset and back on and it immediately started.
I do have a spare pcb card at hand but do not know if this is the source of the problem.
The boiler is serviced every year and every 3 years flushed with fernox.

The last time the vokera agent was here he told me this sometimes happens when the heating/water is selected and you used the hot water constantly.

Can anybody shine any light on this intermittant problem,its doing my head in.

I am a qualified elecky(16th edition) so i can change the card if it is necessary,its only involves plugs on the cards and looks easy enough to do.

Advice needed by anybody whom has heard of the this problem???

Thanks.

 

[Paul Barker]

Sounds like you've had a lot of bad luck. I don't install vokeras but I have no complaints about them. Linea is a pretty well proven design.

Just for the cheapness of it I would change the dhw thermister first.

A nearby firm who do fit vokeras all over the place tell me you can fit the linea28 plate heat exchanger to the 24 to improve hot water performance. I would save that for when you need one, but useful to know about.

Can't help wondering if you have suffered some wrong part swaps over the years.

How do you find that 10mm tne? Your jobs a challenge too isn't it? Don't you think those wires are unnecessarily thick?

 

[coltmanneil]

I do also have a small sensor which fits in the pipework as a spare,but i dont know whether i would have to drain the system down to fit it.Most of the sensors i work with are usually fitted into pockets.
The book or parts manual shows a thermistor and a saftey thermostat which looks very similar in the book.
I can change this ,is this what you refer to as dhw thermistor???

I have many friends and family whom do have similar boilers but never experienced one problem whatsoever.

I am just unluckly i guess.

 

[Paul Barker]

On that boiler it has blue plastic on it and is on the small vertical pipe behind the gas valve. It is a wet one.

After removal of the gas valve what I do is get the new one ready with a little Jet Blue on the seal part for good measure, get my Bahco small adjsutable spanner out and undo old one to last bit of thread which is about to let go, by hand finiush it and quickly stick thumb over hole. A jet of water shoots in your face for a millisecond. Have new one ready, remove thumb and rplace with new thermister, another jet of water hits you in the face.

Beats causing problems with prv seat, leaks from flow return isolation valves, and hassle of a full drain down refill.

It depends on a number of factors whether I perform this wet method, most important of which is my assessment of whether the householder is a sensible level headed person or a twitchy houseproud irrational over demanding perfectionist layabout with nothing better to do all day but clean house and then polish it, who the moment I leave her threshold will call her old plumber "all is forgiven" and will ring me "just send me a bill for what you've done so far, my old plumber just happened to pop in and since he's familiar with the installation he's going to take it from there".

 

[Agile]

Before changing the thermistor, check its resistance. Look in the book but I think its about 10k cold and about 2 k hot. There is one for CH and one for DHW.

If the thermistors are OK then there might be a minor fault on the PCB and if you have one you could see if that cures it.

Its unlikely to be a problem but you could also check the contact resistance on the APS.

Tony