Click here to Find a Contractor in your area.
Welcome! Here are the website rules, as well as some tips for using this forum.

If you've found help here, check back in to let us know how everything worked out.
It's a great way to thank those who helped you.
Need to contact us? Visit

Converting Purepro Trico P3D to chimney vent

Ray_FrechetteRay_Frechette Posts: 25Member
I have the option to purchase a used Purepro Trico P3D direct vent boiler with a Riello BF5 burner for an attractive price.

I would be installing it in a building with a chimney and direct vent through wall is not desireable.

What would be involved in converting it to chimney use? From what it looks like, i suspect the only difference between the Trico P3 and P3D is the choice of the burner used. I suspect the boiers both have the same block.

Can the BF5 Riello be converted for chimney use or would I need a different burner?

Thanks in advance.


  • Ray_FrechetteRay_Frechette Posts: 25Member
    Purepro Trio, not Trico. Autocorrect strike again....
  • STEVEusaPASTEVEusaPA Posts: 3,691Member
    Hopefully you properly sized the boiler to the heat loss otherwise it’s no 'deal'.
    If the chimney meets NFPA 211 guidelines, and you meet NFPA 54, Air for Combustion and Ventilation, you should be ok, following the instructions in the manual for venting-chimney connector, flue pipe diameter and thickness, barometric damper, etc.
    You also have to consider low flue temps, condensing and possible a liner. Are you sure you can’t direct vent it?

    If it ships with the 4” fresh air intake for combustion air, you should use it and bring in combustion air from the outside.
    You are also going to have to consult the wiring diagram regarding post purge, as direct vent burners require (and will be set up for) post purge, which isn’t usually used with chimney vented Riello's.

  • Ray_FrechetteRay_Frechette Posts: 25Member
    Bf5 burner specced if use for direct vent and f3 is used when shipped for chimney use. Looking at the setting guidance the nozzle is .50 on the bf5 and pump pressure of 200 psi with air gate at 3.26 vs .55 nozzle on f3 pump pressure 175 psi and airgate at 2.5.

    I also note higher over burner positive pressure at 0.04 as opposed to 0.02. I assume in part due to fact there would not be the negative draft of the chimney.

    So other than ensuring a proper installation to the chimney , sufficient stack temps, and rewiring burner to eliminate the post purge, all should be good?

    Leave pump pressure and settings as specced for direct vent? Accepting of course fine tuning air setting with combustion test....

    I have done a room by room heatloss calc using Siggy's computer program heat loss pro and this is good
  • STEVEusaPASTEVEusaPA Posts: 3,691Member
    I'm curious about why it's such a great price? Damaged? "Fell off a truck"? Wrong order?
    Can't image it's that much cheaper than ordering the right burner for the application.

    Riello used to just offer a 1 burner (in different sizes) and an option for combustion air intake. Which was achieved by cutting in an adapter to the cover, or using the knockout. Now they eliminated that option and make you select a regular or a BF.
    I think you are still going to have to at least hook up the adapter to bring combustion air into the burner.

    Your settings are only a starting point and need to be fine tuned with your smoke gun, draft test and combustion test. I would start with the P3 F5 settings if your chimney venting, rather than the P3D F5 settings, which is lower over fire draft.
  • Ray_FrechetteRay_Frechette Posts: 25Member
    Someone just bought a house and is changing the entire heating system. He wants it all gone. Boiler, indirect tank, oil tank etc. It was all installed 6 years ago.

    Since The Wall asks for no pricing info, I will respect it. However it is an attractive offer even If I opt to buy a new Riello F3.
Sign In or Register to comment.


It looks like you're new here. If you want to get involved, click one of these buttons!