Jaguar 28kw fault 3 error

[a1colly]

Hi all

Hoping someone can help.

I've a Jaguar 28KW boiler which has had a persistent fault for around 12 months now...

The HW runs fine without any issue,, however, the CH keeps overburning by around 10deg and then cutting off either with error code 3 or nothing - the CH then needs to be turned off and turned back on to get it to fire again or left for around 7 mins.

Ive had several people come and look at with all off the following been looked at tried and tested

new pump
additional pump due to lack of power (ummm)
sludge - all rads and heating pipes cleaned and flushed.
replacement sensors

the whole boiler has also been stripped and cleaned.

im drawing to the end and am now looking at buyin a replacement boiler if i cant find a fix

any help appreciated

thanks

 

[Toolie]

has the central heating output been set correctly?


Setting the central heating output
The central heating output must be set in accordance
with the system requirements.
Setting procedure as follows:
• Push and hold the Bar/Mode button for at
least 8 sec. The display will switch to service
mode, the symbol n- will be displayed
• Set the desired output value from n1 to n9
by means of buttons (7) and (8 according
to the following table:
HEAT OUTPUT
Jaguar 23 Jaguar 28
kW (Btu/hr) kW (Btu/hr)
n1 . . . . . . . . . . . 9.3 (31 732) . . . . . . . . . . . 11.0 (37 532)
n2 . . . . . . . . . . . 11.0 (37 532) . . . . . . . . . . 13.0 (44 356)
n3 . . . . . . . . . . . 12.0 (40 944) . . . . . . . . . . 16.0 (54 592)
n4 . . . . . . . . . . . 14.0 (47 768) . . . . . . . . . . 18.0 (61 416)
n5 . . . . . . . . . . . 16.0 (54 592) . . . . . . . . . . 20.0 (68 828)
n6 . . . . . . . . . . . 18.0 (61 416) . . . . . . . . . . 22.0 (75 064)
n7 . . . . . . . . . . . 20.0 (68 828) . . . . . . . . . . 24.0 (81 888)
n8 . . . . . . . . . . . 22.5 (76 770) . . . . . . . . . . 26.0 (88 712)
n9 . . . . . . . . . . . 23.0 (79 152) . . . . . . . . . . 27.6 (94 171)
n– . . . . . . . . . . . 23.0 (79 152) . . . . . . . . . . 27.6 (94 171) .. max. output

 

[a1colly]

Thanks for the speedy reply

Yes the output ratio is set correctly and just to make sure we've also adjusted it to a lower and higher setting but it makes no difference at all.

 

[Toolie]

did you do a flow test through the two heat exchangers when they were take out to clean?

F3 = heat exchanger blockage

 

[a1colly]

Yes, flow tests were fine

one person thought it might be the PSB as they actually took the boiler of the rad sysytem and it still occured -

 

[Agile]

Apart from setting the CH power did you reset the CH flow temperature to a lower value such as perhaps 70° C.

Tony

 

[Toolie]

if you run a hot tap slow does the boiler flame modulat down

if you adjust the ch temp on boiler control panel down when its running does the flame modulat?

 

[a1colly]

The HW gas flow does modulatedepending on water flow rates.

The CH does not modulate no matter what temp it is set to - if the CH temp is turned down it still burns past.

Thanks for all your help again

 

[Agile]

Has the min/max on the gas valve been set ( correctly ? )

Is the incoming gas pressure adequate at the inlet on full power?

These have a much higher than usual burner pressure.

Tony

 

[a1colly]

Inlet pressure is adequate at the inlet according to resent tests.

The gas valve pressure is also set correctly.

Is there anything else possibly??

 

[Agile]

I would always be more confident that I can assess the situation effectively if I am in posession of the relevant test figures as measured!

Who has made the judgement that the inlet pressure and gas valve settings are correct?

Tony

 

[gazdaz36]

even thought system has been flushed it still points to poor circulation through the heating system if your boiler is working fine on hot water the heating pipework has got to be restrictive