Best Of
Re: Boiler radiator valves siezed
I got most of the 1st floors valves unseized with Kroil and not 3 are leaking, so this definitely has to get done soon. Thanks for pointing that out, I'm new to boiler systems.
It's good to know I can shut this off in the summer so I can pull a radiator in the bathroom to paint and then re-install, fill, and bleed the system!
Re: Boiler radiator valves siezed
you need to loosed them completely and repack with new teflon!

Re: Boiler radiator valves siezed
Do they stop leaking if you tighten the packing? Don't crank on them too hard or you could break the packing nut, but just tightening might stop the leak. If the stems are crusty the roughness of the stem will damage the packing and make it leak.

Re: Packing Heat
I would do the couple of tutorials required to run your place though this:
With a reasonbly accurate model, it is a great tool for answering what if questions like how much would more insulation save or a heating system with higher COP.
For most existing homes, at least in colder climate, usually the best ROI is better air sealing.

Re: Moving radiator closer to wall
Aluminum foil over a thin piece of sheet metal (or even wood or cardboard) the same dimensions as the radiator can be placed against the wall and will reflect nearly 100% of the infrared light emitted by the radiator back into the room. I think about 80-90% of the heat delivered by the rad is through convection, so only a small portion is infrared, but at least it won't be wasted through your walls.
Re: Bosch Greenstar Combi with excessive exhaust / Intake condensation
Replace the flue connector: it’s leaking between the pipes.

Re: Adjusting the Offset
I suspect it isn't that it is damaged but that it is so far out of adjustment that it is very difficult to get it back in the right range without a test rig of some sort. BTW the manufacturers of that valves have much more in depth documentation than what HTP gives us.

Re: Repair or Replace Gas Boiler
You got a long run out of that Tlyne-Laars...That's not even a company any longer, but Laars make a really nice replacement. Mad Dog
Re: High delta T losing hot water
My suggestion is more data collecting and actual observation and onsite trouble shooting.
I think you have a similar type of building, does a heat load of 90,000 btu/ hr sound reasonable for a 2000 sq ft duplex? 45 btu/sq. ft
These are one bathroom units, how much DHW is needed, expected, required?
What is the boilers actual output? Is it a 205 or a 206?
How many feet of fin tube in each unit?
Have the tenants been in the units for some time? Are these new problems, or have they always existed?
If the indirects are not on priority, that could be a simple, good upgrade if you want to maximize DHW production. From the pic we have, it looks like each zone has a good purge point.
I'm not convinced repiping or pump and copper upsizing is the next step with so many unknowns?
