Zone that doesn't heat properly

ntonkin

Gordy said:

The trick from here is to throttle all the zones so they heat effectively yet not over power the hydro sep when all are calling.

Any zone with baseboard should only need between 2-4 gpm. Favor 2 to keep air entrained.

The radiant zone 5 has flow meters. I don't know what flow they are set at, but the loops should be running between .5, and .75 gpm. So you could throttle that pump to where the flow meters are still showing the indicated flow you are set at.

The zone with the copper pipe in floor, and baseboard may take a little experimenting. Maybe 2-4 gpm.

Now is a good time to use those strap ons to check supply in and out on loops to see where you are at.

Zone 5 flow meter are set at 2 gal/min I think that can be adjusted with the valves but I don't remember how to do it. It's a Viega mixing valve as you can see in the pictures posted previously. "throttling the return on the zone has no effect on the flow to the pex loops.

Gordy

Are both loops at 2 gpm? Or 1 gpm each loop? Pull the red locking cap up 1/4”, and then turn locking cap clockwise to decrease flow, or counter clockwise to increase flow. When done adjusting push locking cap back down.

ntonkin

Gordy said:

Are both loops at 2 gpm? Or 1 gpm each loop? Pull the red locking cap up 1/4”, and then turn locking cap clockwise to decrease flow, or counter clockwise to increase flow. When done adjusting push locking cap back down.

Both were at 2 gal/min - I adjusted them both to a little above 0.5 gal/min.

ntonkin

firing% 20
boiler in 179
boiler out 185
system 173
delta T 4
flue temp 205
Secondary out 173
Secondary return 169
zones calling 5
Outside temp +22

I think I have the strap-on thermometers calibrated reasonably well and will get them on zone emitters in the morning. I assume I'll need to have the measured zones firing when I'm recording the in and out temps, right?

Do I need to measure Zones 3 & 6 as they have the Alpha 2 pumps that measure flow?

Gordy

how Is everything heating?

You can check which ever zones you want. Probably all eventually.

I’d take that radiant zone back up to 1 gpm each.

SuperJ

Ntonkin, you basically want to keep reducing flows until the delta on the secondary side is at least 20degF when everything is calling (except zone 5, it's an oddball with the infloor and mixing valve). The reason for 20deg is that equates to about 10gpm or so when your boiler is at full fire, and is about the upper limit of your hydraulic separator for flow.

I would throttle every zone pretty harshly and only re-introduce flow as necessary and after you've got the secondary total flow under control.

Also, your boiler is probably running a bit more aggressively than it needs. If you're able try enabling the ramping function (installer settings). Maybe 5-10min at each level, so that it won't be allowed to run at 100% unless it's been running for 30-45minutes.

ntonkin

Gordy said:

how Is everything heating?

You can check which ever zones you want. Probably all eventually.

I’d take that radiant zone back up to 1 gpm each.

Zones are heating ok, although it is pretty warm out now.

I cranked both the garage loops up to 1.0 gpm

I'll start with the strap-on thermometers this afternoon.
Daughter and grandson are visiting right now.

firing% 22
boiler in 160
boiler out 166
system 160
delta T 6
flue temp 165
Secondary out 161
Secondary return 129
zones calling 5
Outside temp +29

Gordy

It's like @SuperJ posted you are just seeking to balance the zones. It takes time.

ntonkin

SuperJ said:

Ntonkin, you basically want to keep reducing flows until the delta on the secondary side is at least 20degF when everything is calling (except zone 5, it's an oddball with the infloor and mixing valve). The reason for 20deg is that equates to about 10gpm or so when your boiler is at full fire, and is about the upper limit of your hydraulic separator for flow.

I would throttle every zone pretty harshly and only re-introduce flow as necessary and after you've got the secondary total flow under control.

Also, your boiler is probably running a bit more aggressively than it needs. If you're able try enabling the ramping function (installer settings). Maybe 5-10min at each level, so that it won't be allowed to run at 100% unless it's been running for 30-45minutes.

Is this the section on page 23 & 24 of the service manual on enabling ramp delay?

SuperJ

Yes the ramp settings are described on page 23.


Also, this doesn't replace the balancing effort that we've already described. In fact I would try and get your separator secondary in/out delta when all the zones are calling to and the boiler is at 100%, close to or above 20degF first.

Putting the thermometers on the return line from each zone will help you identify which zones are flowing too much. Basically if the return is coming back hot your are flowing too much water. There might be one or two zones (3 for example), that need more flow (hotter return), but even then I think you should be shooting for 20degF or more everywhere, and no less than 15degF if you are having trouble heating.

Basically you can set 6 ramp limits points and 6 times.
The longer it runs the higher the ramp limit it may get too. This should keep it at lower more efficient modulation and temperature on short cycles.

I would probably limit it to 20% for the first 5-10minutes, and then slowly raise the limit every 5-10minutes to the next one.
It seems counter intuitive but long low heating cycles generally are more comfortable than fast blasts of intense heat.

Once you get the flow under control, there are some optimizations on your boiler to do:
-Get Outdoor Reset Working
-Properly wire and configure different heat loads to different setpoints. (zone 5 infloor should be able to run at much lower temps than 165)
-Ramp limiting to keep things low and slow and efficient
-Potentially enable the boost to ensure that when the set point is low that eventually the zone will get the heat it needs if it runs long enough (the boost settings slowly raise the set point as the boiler runs, letting you start with a lower initial set point.)

Can you ensure the boiler is set for outlet sensor?

ntonkin

My heating system is working immeasurably better and I think that with the wealth of information you guys have given me, I will be able to tweek it to the optimal level of performance. I can't thank you enough . . . especially Gordy and SuperJ . . .Thank you so much.

Gordy

Good to hear. Can you tell us where you ended up? As in throttling the zones, and did you tweak the ramp delay?

ntonkin

I'm still working on throttling the zones to get around a 20 degree delta. The painter's tape on the pipe really works amazingly. It may not make it real accurate but it's stable and close enough to make it usable. Once I get the zones throttled I am going to start on the outdoor rest and ramp delay. I can't really focus 100% on this at the moment as we have our 4 year old grandson to watch while his parents are making a cross-country move. As I complete the phases, I will report results though. Anyway, I owe you guys big time.

Gordy

Remember don’t get to wrapped up in the delta at the emitters. It’s not a fixed number only to design around. What could be a 20 delta on a 20 degree day may be more on a 0 degree day. So try to do that throttling under like outdoor temp conditions. Preferably at colder outdoor temps.

The grandson would love to help gramps I’m quite sure!

ntonkin

I installed (flapper) check valves on the returns from all six zones, flushed the system, ran cleaner for a few days, flushed and drained the system and filled with distilled water treated with Hercules Sludgehammer corrosion inhibitor & Hercules system cleaner. I did get quite a bit of crud out of the Califfi after running the cleaner. I am getting a Bacharach 24-8511 Fyrite InTech combustion analyzer this week and plan on restarting the system tweeking again as soon as the cold weather sets in.