Oil Boiler Piping configuration Review

avsmillar

I bought a home last year with a brand new Lennox COWB-3 Oil Boiler and a none functioning piping configuration. I would like if someone with much more experience than me reviews my drawing and tells me if they see any major flaws. I am using a Caleffi Hydro Separator and Grundfos Alpha pumps for the zones. A pre-existing one speed Taco pump will be used for the primary loop. I am using several pieces from the existing system to save money but the ALPHAs and seperator are new.

Rich_49

Think about piping that expansion tank and make up water remotely to the bottom of the Sep 4 and eliminate that tee .

That is quite a few circs . Any reason not to use zone valves besides preference or advice from someone ? Have no idea of your flow rates but most jobs can be done and work very nicely with 1 circ and zone valves .

Zone 4 may require some balancing if both do not have like resistance , the branch on the left could quite possibly see more flow and heat than the right if they are not like . If the left branch has more resistance you mat be good .

I am guessing there is no outdoor reset on this arrangement . If you do wish to utilize it don't forget boiler protection .

What size COWB3 is this ?

Steamhead

Those Lennox boilers are actually made by Dunkirk. Do you have the full model number, i.e. COWB3-#? If not, what is the rating of the boiler? Which Taco circ do you have (probably a 007?)?

avsmillar

The COWB3 is a -3 (3 body). I am not sure of the one off circ pump but, its black. I will provide the info later tonight. This is really great to be able to get advice and info from others interested in the same things. I appreciate your time. I went with the circ pumps because my boiler efficiency was tuned but, was not getting enough heat from baseboards. I could put my cheek against any one in the house. I have a two story and zone 6 was the only one on the second floor. The pipes had frozen up their several times during its history because I saw three burst pipe lines tossed aside in the crawl space. All from the same length of the run. I will also send a photo of the current configuration but I am certain that the primary loop tees are not close enough and may be causing much of my issue. Maybe you can advise. I bought the 6 pumps but would be glad to use my zone valves if I can get a good result. Stay tuned.

Rich_49

What drove your decision to use a hydraulic separator for this arrangement ?
That black pump is probably a Taco 007 (oem stuff) . Was there zone valves before with a single pump for all zones ? If so , do you know which pump it was . Quite possible that ti could not move the amount of water necessary through all zones or several when calling . There also may have been air retarding flow causing your frozen lines .
Interested to know how big this home is and more about how it is zoned , how many feet baseboard , Equivalent lengths and the like . Would be a shame to do all this work only to encounter a problem from something overlooked .
Did you use any online heat load programs to perform a heat loss , room by room ?

hot_rod

Is this a fin tube baseboard or cast radiator application?

If that is a cast iron boiler with very little pressure drop, really no need to have a hydro sep involved, either with multiple pumps or zone valves.

If it is cast iron radiators and large water content a boiler return protection device could be worth a look.

One smart pump and zone valves might be a better setup.

Some good ideas in this journal about zoning options.
It's a few years old, but the theory and math is still relevant.


http://www.caleffi.com/sites/default/files/coll_attach_file/idronics_5_0.pdf

avsmillar

Rich, Bob, and Steamhead,

Below is a picture of the current setup. As mentioned, it didn't work well. It could not heat the house past 63F when outside is 0F. It is a fin baseboard configuration throughout the house with 2 radiators in the garage that I isolated with the hand valve b/c I do not use them. A HVAC company performed a heat rate calc and said that I am a little short of appropriate base boards for the space but that it would not affect the house like I was seeing. The COWB3-3 could support the load. They tuned the boiler and in the next month I went through over 400 gallons of heating oil. I had them change the nozzle back the next month.

Estimate of square footage of home is about 2600.

Zone 1
34 ft master bed
4 ft master bath

Zone 2
38 ft Great Room (18 foot chalet ceilings with lots of large windows)

Zone 3
15 ft Dining Room
8 ft kitchen

Zone 4
25 ft guest room
9 ft guest bathroom

Zone 5
11 ft in basement
Two 26"X30" radiators in garage (not used)

Zone 6
15 ft upstairs room
6 ft additional upstairs room

I decided to go with this setup after a summer of learning about boilers. I am no expert and thought that a separator would be best to ensure that the zone pumps did not wreak havoc on each other and the primary zone. I assume that the circulator was the issue with the old setup but was not sure how to add a circulator without having issues with the upstairs zone (Baby's room). I figured each zone circulator would solve any differential in resistance for the zones. I made sure to bleed all zones thoroughly of air for my first attempt at fixing the system last winter. The system is well equipped to bleed air.

I forgot to change zone four in the original drawing. It will be separated. The original setup was 5 zones with zone 4 split. I also realized I used "demand" instead of "return". The existing circulator is a Taco 007-F5. There is no outdoor reset but, would not be opposed if it will help.

I live in PA and is was really cold last winter. I have a 9 month old and I need a solution that will work. If you recommend a cheaper solution, I am all ears (or eyes).

Rich_49

Where in Pa are you ? Don't do anything yet . Keep everything you bought in it's packaging . You DO NOT NEED all of that stuff . Please tell us what measures the HVAC company took to perform the heat loss calc ?

avsmillar

They measured each room and took in account the insulation and internal gains (sunlight and consistent basement temp). Then they measured the baseboard and radiators. Not real technical from my point of view. That is why I tried to tackle it on my own. Just to make me feel better, do you think the setup I drew would work?

Rich_49

So you are near Pittsburgh ? What town ? Do you know anything about how your home is insulated (or not) ?

avsmillar

Oh yeah, Pittsburgh.

Rich_49

Have you used the find a contractor feature here on the site ?

avsmillar

New Castle. 45 minutes North. The house is a original 1920 home with a 1980 addition. The original home was reinsulated. I added new R46 to the crawl space walls of the babies room but I assume the same low R value I found is in the roof walls. It is an attic bedroom.

Rich_49

How far from Kittanning ?

avsmillar

It is all fiberglass, both loose and batts that I have found.

avsmillar

So what do you guys think? Return the stuff? My concerns are by only using a smart pump in place of the Taco 007 in the original setup that the only zone going upstairs (babies room) will have very poor heat when multiple zone valves are open due to lack of flow.

If I put in an additional pump instead of the valve just in that zone (babies room) then the other zones will have to much back pressure on the common return header to work correctly.

The reason I bought the hydro sep was to solve any issues with pressure differential caused by all the zone pumps if I did install them. I am open to ideas. I can loose the hydro sep and just rebuild the primary loop to put the tees for the bypass closer together (6"-8").

RLuck

Did you confirm all the zone valve end switches are working. A couple dead end switches may give you the same problem. Turn on each thermostat one at a time to confirm it fires the boiler, not just opens the valve.

avsmillar

RLuck, no zones had any significant heat output. I ended up creating a true P/S loops system, removing the hydro separator and using two closely spaced tees 4 X pipe diameter apart. A single circ pump on each loop and reused the original zone valves. The air separator is still in the mail but the system is basically complete. I will post picks once it is finished for review and possible advice for next year.