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BAXI 40ga ignition sequence question

betweentheframebetweentheframe Posts: 97Member
edited March 16 in THE MAIN WALL
I am much happier now that I have eliminated PS piping as baxi said. Couple of q. Right now I have one zone that is 3 radiant slab zones on zone valves, no issues when this calls), I have one 2 zone valve staple up upstairs(which I may slave to the smallest zone I will describe now which most frequently calls for heat). Last one is a loop on zone valve of staple up, flow control all the way open to allow flow accros HX, a loop that is one 24x48 buderus @ 1gmp, and one 24x48 buderus in a spare bedroom on trv(rarely on).

When ignition for CH starts it is a bit loud like the fan runs at max and then sort of turns turboish for a few seconds before modulating down, is this normal as it seems to fire at more modulation for DHW. I still get some short cycling where it hits 176 degrees quickly and shuts down waiting for 10 minute programmed refire delay I set, seems to really have issue when mid heating cycle people use hw or run DW as it gives that priority, then does not wait and refires right away after DHW call and often was mid firing cycle and hits its 176 shut off quickly.

Should this thing be firing at modulation? Could my pcb bpard be bad or the wiring for wrong odr that is now bypassed be bad, waiting for new one cause had installer had wrong model odr installed. I have lowered max % from stock to 45, have running at 140 degrees and have tried to lower max fan speed to 120 to try and stop so much ignition at firing, but I think that may affect DHW as well. I think I need new NTC, because it seems to run DHW at like 140 plus then shut down even though I have set to 118.

These are self calibrating correct? I have run a calibration sequence. But i mean, the gas valve modulates based on its flu sensor and DT on return and supply sensors etc? It does not need to have gas valve adjusted so to speak??


  • SuperTechSuperTech Posts: 938Member
    Every single fuel burning heating system needs to have it's gas pressure set and combustion tested and the air fuel ratio adjusted during commissioning. Baxi is no exception. No unit is perfectly set out of the box. I have found some that run poorly without proper adjustments. You need a professional with the the proper tools and experience to set up a condensing boiler. And you need the outdoor sensor connected.
  • betweentheframebetweentheframe Posts: 97Member
    edited March 16
    Right now I set it to not adjust temp because would not even let me set curves because as baci said, the wrong model number was outside and wrong resistance does not even tell PCB correct info, waiting for part to deliver.

    Yeah, It has air and flu probes slots above on flu termination on top of boiler. Gotcha on having someone with a calibrated meter set up gas valve. But the “qualified professional” that installed this is a baxi certified tech and had it all jacked up and wrong ODR, bad PS (not even proper PS) like a weird loop set up. I am in hudson valley and finding someone smart enough to know more than me is essential and proving difficult(I am a general contractor in NYC and used to work in hvac for friends company, all forced air however).

    I have installed several of my own forced air systems and never had an issue. From w coast originally and hydronic is new to me. But after seeing what this guy did and them anoyher guy look at it and say, looks weird but probably right, does not lead me to trust anyone really.
  • betweentheframebetweentheframe Posts: 97Member
    ODR says max efficiency increase is 2% fyi, that does not seem like a huge deal to me. Really I want to make one manifold downstairs 120degree for better slab performance vs rads and staple up, but trying to logistically figure that out, I guess I would just need to have pump after mix valve and run the manifold return into mix valve with T from where it goes back to boiler (boiler is on closet in kitchen, manifolds and valves are in basement like 16 feet away)
  • SuperTechSuperTech Posts: 938Member
    I'm in Dutchess county myself. We don't have many Baxi boilers around here but it's certainly not impossible to find someone experienced with mod cons and combustion analysis. But you will definitely find plenty who aren't. If you want I can try to make a recommendation depending on where in the valley you are located.
  • betweentheframebetweentheframe Posts: 97Member
    edited March 16
    I’m in saugerties in Ulster county, you a tech?
  • SuperTechSuperTech Posts: 938Member
    Yeah I'm a service technician from southern Dutchess county. I've worked as far north as Kingston before. I can't say I'm familiar with any companies out your way unfortunately.
  • betweentheframebetweentheframe Posts: 97Member
    edited March 17
    Sent you a private message, if you want text or call and come out my way I can pay you to calibrate, look over and then may have more work in fall when I do a radiant slab and add a couple rads and get rid of staple up in a small reno I am doing. Saugerties does not license trades, only kingston proper. So no issues there
  • betweentheframebetweentheframe Posts: 97Member
    Or email me at [email protected]
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