I'm a HVAC newbie and I just finished installing my Garn. I installed about 20' of 1.25" copper to do this and some 1.5" and 2" black iron. I found this thread very useful, and I wanted to share a few of my findings in case they help someone searching over the coming years.
First, NO LEAKS! Incredible....and very very pleased.
1. Cleaning copper takes forever. I spent likely 3-4 minutes cleaning a fitting with a 1.25" brush and likely 5-7 minutes cleaning each 1.25" pipe end. I don't know if one needs to, but I try and sand down the "horizontal scratches" one has on the pipe inside the fitting. Seems like these could be easy leaks....so it is worth a little time. If you can have a helper to sand/clean....do it. It just takes so long. 50% planning, 40% cleaning, 10% sweating....time usage.
2. Make sure there are no brush hairs in your fitting or on your pipe in the flux. I also looked carefully.
3. Put a number of fittings/pipe together and then sweat them all at once.
4. This 1.25" pipe isn't likely sweating 1/2" or 3/4" pipe. It takes more heat and uniform heat isn't just a given like the smaller pipe. You have to move the torch around.
5. 1.25" ball valves and etc. are big...they take heat...but don't overheat!
6. Don't use too much solder! I wrecked one fitting when solder ran down over the threads. I also wrecked a Webstone Pro-Pal valve when the inner ring drooped. I think perhaps I turned the valve too early...though I think too much heat was involved too.
7. Give yourself an easy way to drain the tubing should you need to, i.e. at the lowest point. If you have a leak, and you need to reheat, you have to be able to get the water out. I didn't need to, no leaks!, but I put this in.
8. Though heaterman says no Benzomatic, and I take his words around here like Gospel (save the politics), I used the Benzomatic and Mapp gas. I already had it...
9. Put in all the valves and fittings you can think of....easy way to rinse out the HX, strainers, isolation, etc. and so forth.
10. Wipe your joints with a dry rag....what a differnce this makes in how it looks.
11. If you can, assemble what you can on your workbench...so much easier than doing in place (well, was for me anyways...installed height is low to the floor).
12. They make teflon tape in 1" width...and with big pipe, it sure is nice compared to 1/2". Find some and buy it.
13. Teflon tape and pipe dope....no leaks!
14. Home Depot doesn't have nipples in 1.5" and 2", especially 2", in many lengths. But a real plumbing supply store will have them in every 1/2" or so.....and their prices were often cheaper (for copper) than the box stores....and they don't have a damned sticker on every fitting. Look their first....and they know what they are doing.
15. Make sure the joints on the valves are tight. I did have one a little loose out of the box.
16. Setup a pressure test if you can....or test sections if possible. I was able to assemble all the copper around my HX and test it all. You can use a garden hose and a washing machine supply line to connect the garden hose to a boiler port. Extremely quick and easy and you can test at water line pressure before hooking it all up and flooding...and draining if need be.
17. Custom cutting black iron at the box store or plumbing supply...no big deal...and if it will help make your job easier, just do it. Usually it is free.
Hopefully some of this may help another newbie. I surely spent more time thinking about it all then actually doing it. You can do it yourself...Have fun and don't plan on getting it done quickly. And oh yes, you will spend considerably time just getting all the fittings/stuff you need. Even after you think you have it all.
Bruce