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

Installing condensing combi boilers or heating boiler only.

bob eckbob eck Posts: 857Member
My question is when installing condensing combi boilers or heating boilers only that are wall hung I see some contractors prefab the near boiler piping on a board in their shop. When doing this prefab in your shop before the actual installation how much time does this save you on your installation in your customers basement?
Any photos or videos of how you are doing it would help.


  • EBEBRATT-EdEBEBRATT-Ed Posts: 5,730Member
    Large mechanical rooms in new commercial jobs I have seen the entire job on a CAD drawing. All the pipe is cut at the shop and trucked to the job and then assembled.

    Usually there is a minor mistake or two if you have a good cad guy. Labor savings is tremendous.I have had people tell me that even if 20% of the fab is wrong it will still come out ahead.

    I am not convienced. Propress fittings are expensive to scrap.

    Need someone who can draw and measure the job. That's the key.
  • hot_rodhot_rod Posts: 11,394Member
    I found on residential work, the retrofits work pre-built panels work out well, but new homes you really need a GC willing to protect your turf.
    On a few occasions the panel I built arrived and my staked out wall space had water heaters and and furnace installed, or was shrunk down from my panel dimension.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    The magic is in hydronics, and hydronics is in me
  • GroundUpGroundUp Posts: 504Member
    Seldom does prefabbing save me any time. Most cases, it takes extra time to prefab unless the jobsite is a totally blank canvas and can accommodate carrying an assembled panel inside. Building a boiler assembly on site has never taken me more than a day, start to finish including gas, venting, flush/fill, startup, CA, etc. Prefabbing saves maybe an hour on site, but takes 4 hours in the shop after you take into consideration the time it takes to do everything twice- tear the truck apart for tools, clean up, etc. As long as you take a complete material list and have everything there, I see no benefit to prefab. If a guy had 2 full sets of tools and a "fab shop" set up at home with everything right there, that'd be another story but most of us do not. The theory is great but the reality is that it saves nothing, for me at least
  • Tom_133Tom_133 Posts: 619Member
    My savings comes from working at my shop, which is only 300 yards from my house. No driving, have everything delivered, wire it all ahead of time, do all the little things that drive me nuts ahead of time and take my time. Even friends stop in for a chat. Maybe not a lot of "savings" but for me sanity is a plus
    Montpelier Vt
  • DZoroDZoro Posts: 756Member
    Building it in the shop to me is more of convenience. I can work on it in between service calls, phone calls, before work, after work.... Then I'm not so rushed on install day, doesn't make for a late day, or rush to get it done. For one guy a complete combi set up start to finish at the job site makes for a very long day if not 2 days. Don't work as fast as I once did, and don't want to either ;).
  • Robert O'BrienRobert O'Brien Posts: 3,107Member
    Prefab almost everything
    To learn more about this professional, click here to visit their ad in Find A Contractor.
  • R ManninoR Mannino Posts: 434Member
    Saving time. Can it really be saved? I think it's mostly a matter of where you spend it. I am more efficient in a shop setting because the tools are always in the same place, the environment is how I how I set it (we are in the HVAC business). I believe my work is of a higher quality when I am in my shop as opposed to someone's basement.
  • SeanBeansSeanBeans Posts: 301Member
    I used to have two guys ripping out the old boiler and I would be out on The driveway piping away, return, supply.

    I’d do the LWCO wiring and everything In The driveway, they hated it!
  • Solid_Fuel_ManSolid_Fuel_Man Posts: 1,502Member
    @R Mannino

    Just to avoid working in that little 4 foot space!
    Master electrician specialising in boiler and burner controls, multiple fuel systems, radiant system controls, building controls, and universal refrigeration tech.
Sign In or Register to comment.


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