Baxi Barcelona, which has been upgraded to 100He spec
On the original control board there were 2 jumpers .. Both were removed as this boiler is connected to a thermal store
J1 to set to 100,000Btu/h J2 to turn off modulation
New board has 4 jumpers J1 Red J2 Blue J3 Blue J4 Yellow
Am I correct that J1 & J2 are the same .. and therefore should be removed ... and removing J3 should also be done to prevent limiting of output temperature
J4 remains as this is a standard short flue
...REMOVING< Jumper 1 limits the output to 52,000 btu's Jumper 2 Increases the output to 100'000btu's Jumper 3 limits the flow temp from 82°C to 63°C - optimum condensing temp,thermal stores Jumper 4 provides low gas rate ignition sequence, for long horizontal and vertical flues
so 2 and 3 out in your case If you are still having explosive ignition problems remove J4 Phone Baxi for confirmation
-Are you sure that I should have jumper 1 in place ?
Looks like Explosive ignition issue may now be resolved (earth wire harness issue) so left 4 in
I found a later manual on-line:
page 22: If the installation requires a greater output to achieve the desired room temperature, this can be increased to 31.18 kW (103,000 Btu/hr) and the boiler can be adjusted as follows: a) Draw the control PCB forwards out.. b) Remove all three jumpers.
If the boiler is to be used in conjunction with a Thermal Store, the boiler can be adjusted as follows: a) Draw the control PCB forwards out .. b) Remove jumper 2
Just seems a bit odd ... remove 1,2 & 3 for 100,000Btu/h But remove only J2 for thermal store
also found this on-line ... has even different recommendation:
post#5 advises set jumpers to: 1 in, 2 out, 3 in for Thermal stores
So far convinced 2 to and 4 in are correct, still unsure about 1 & 3
Finally found the official answer - got a Tech note from Baxi, may be of use for others:
System up to 75,000 Btu/Hr Ji in J2 in J3 in
System up to 100,000 Btu/Hr J1 out J2 out J3 out
Thermal Store compatibility J1 in J2 out J3 in
J4 in for normal flue, out for long flue, and slow rate ignition
I admit i don?t know much about thermal stores but would have thought that it would be better to limit the flow temp to
63°C for optimum condensing temp i.e J3 Out-
Trying to get 'best advice' not easy ... but the above at least is how jumpers work. The store is set to 60C currently can't be set higher due to Underfloor Heating - I may fit a blending valve to allow store temp increase but limit loop to 50C
NuHeat advised setting temp on flow to 75C to ensure fast enough recovery time on HW in tank when fro exampling running a bath.
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