pumping away from point of no pressure change !!!

newagedawn

the latest install and that pumping away technique." it works much better than the old system" said the home owner who had 3 pumps on the return, one for each zone??? and i know he loves his 30 degree high limit boiler dif

HVACNUT

Nice job.
I'll use 3 circs over zone valves any day.
No Riello?
I can't believe people still opt for a tankless over an indirect. He'd probably like the benefits of ODR over a 30 degree diff.

ChasMan

Those tankless coils cost next to nothing, indirects? That's why, plus they lived with them all their lives. Around here you see the odd baby with frog skin, that's a tankless baby.

Zman

I like it!
A nice, simple, clean, system.
Nice workmanship

unclejohn

I think i'm the only guy who still solders everything.

SeymourCates

@newagedawn

The 30 degree diff on the CI system is brilliant. Operate it at an SWT of between 150F and 180F for the maximum possible run time provided the system can make the heatloss at an AWT of 157F (highly likely).

Trying to use OAR to provide similar results will definitely result in shorter run times and kill the efficiency.

Additionally, zone valves are always preferred due to the massive overpumping of the zone with the classic Taco 007 (with DT's in the weeds). Sure, you can try to use a Taco 003, but nobody is going to bother with that.

Alan Welch

Is the coil feeding a storage tank? I don't see a mixing or relief valve.

newagedawn

@SeymourCates
yes, this is a baseboard system so i ran the high limit to 190, so the swing is 190 to 160, and yes i agree with you on the over pumping when using pumps on all zones, greatly diminishes the efficiency by running the water to fast through the boiler when more than one zone calls for heat, all that system needs is 1 pump for all the zones, its 12 GPM with a 6ft of head = 1 pump

newagedawn

@Alan Welch
the relief is in the back on peerless boilers and there is no storage tank from the HW coil, if he wanted that i would have done indirect, this is in a closet and not alot of room, and no mixing valve, the person likes his water hot, its a person to person thing for hot water

SeymourCates

@newagedawn

Nothing wrong with 190F to 160F if you actually require it. That would offer an AWT of 170F with a 10F DT (unlikely you'll do better with a conventional pump). A quick heatloss and baseboard survey would tell if you can reduce. Many times you have much more than needed at 170F AWT.

I have been successful with 175F/145F in several buildings. I try it and wait for the phone call. Surprisingly, it never comes. An outdoor reset cannot accomplish any better result and will typically short cycle the boiler at the lower temps and traditional diff (20).

newagedawn

@SeymourCates
interesting! when i go back next yr to tune it up i will try that temp range and wait for the call, lol, that will also save him money, i like that ! and i totally agree on the ODR

Alan Welch

I was referring to a relief valve on the coil. Where I am located , mixing valves and relief valves have been required for as long as I can remember. With boiler water at 190 degrees what comes out of the coil can scald you quickly, it happened to one of my children years ago when mixing valve failed and bathroom sink was separate hot and cold faucets.

Danny Scully

Another tip @newagedawn, I usually put the zone valves on the return. This help prevent any hammer caused when the zone valve closes and the circ still runs for a bit. Also agree with the relief valve/mixing valve necessity on the coil.

hot_rod

Also, depending on the valve listing, thermostatic mixers should fail cold and not allow scalding?

Some of those hot water "extender" valves are not scald guard type.