Boiler Wiring question


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Old 12-18-09, 10:32 AM
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Question Boiler Wiring question

Just bought house
Here is what I know
1964 American Standard Arcoliner wideback with General fittings tankless (estimated original cap 5GPM) 164,000BTU/hr Newer Becket burner
Hi Limit Detroit Lubricator (Breaks burner line voltage on temp) Set at 185 Deg (Coasts up to 200+ ) Closes at approx 160 Deg
3 taco 007 circulators with 3 American Standard relays with terminals for TT and SS(stack switch is non existing but looks like they are wired and either cut or jumped together)
3 luxon programable thermostats (new to replace old Honewell mercury round)
I assume thermostat controls circulators only but not sure.
Here is confusion.
SPDT American Standard aquastat in tankless well is wired NC(normaly closed)
back to TT on burner relay (however, it is always closed, I am assumining it is malfunctioning.) it is wired in parallel with wires going back to circulator relays but not sure why. I think that it is just a complex (cobbled) way to jump TT on burner relay. Possibly an attempt to disconect circulator and fire burner on low temp but not sure how. Not sure when NC opens( above or below adjustable setting)
On back is White Rogers 11d31-1 spdt wired to close on rise to break line voltage to circulators. Adjustable differential is set to as close to 0 as possible
If not set to 120Deg or below, circulators will not turn on and boiler will hang a few degrees above 160 deg on hi lim switch.
Is it normal to have such a differential from top (temp/pressure guage and lolim sensor? It seems like a rather primitive way to control.
Is boiler just bouncing between differential on hilim switch.
what about thermal shock? Should of cracked a long time ago.

30 deg outside with all 3 circulators calling for heat, boiler drops to 130degs and I still have hot water for shower. Tankless does have 30 gal aqua boost with its own circulator and separate aquastat.
heating approx 3000 sq/ft (1000 per zone) Have not updated insulation yet. NG will give me $2k rebate
Slantfin heat loss calc says 67,000 BTU/hr at 9 degree dt.
Insulation will reduce to 61,000BTU/hr

any advice/insight
would Intellicon HW+ help save $ or just lower differential on hilim? Would circulators ever turn on?


My oilman suggest putting a couple of firebricks in the upper chamber but was not clear on how many or where.
He seems to think it is a great boiler. He can not remember how old controls should be set up however.
They replaced the quickee chamber and blast tube. It was clearly hacked by previous owner's oil guy. chamber was broken and tube had hole burned in it because it extended to far into chamber.

Been reading threads for a couple of months and only advice I got from experts on another site was to buy a new boiler.
Thanks. I need this one to last for awhile due to budget constrainsts
fredhhh
 
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Old 12-19-09, 10:59 AM
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Fred, I can 'sorta' understand what's going on with your system, but pictures might help fill the missing pieces... and even better yet, even a scribbled up schematic might help with understanding the wiring / controls...

You can upload pics, etc to a free account at Image hosting, free photo sharing & video sharing at Photobucket and place a link to the album here.
 
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Old 12-19-09, 11:40 AM
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new insight

NJ,
Will do.
Meanwhile I solved one piece of puzzle.
I originally assumed that thethermostats only controlled circulators.
Once I disconnected the 24 volts to tankless aquastat which seems to be permanently closed and acting as TT jump,
burner is now firing on call for heat and shutting off when call is satisfied. I assume it is now acting as a cold start boiler. Not sure how to test that theory other than turn down t-stats and wait.
Not ideal with tankless.

I am alsowondering if the White-Rodgers 11d31-1 spdt can be used as circ cut out and low lim switch.
I will send pics as soon as I set up Photobucket
 
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Old 12-19-09, 12:57 PM
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links to photos

1964 Arcoliner pictures by fredhhh - Photobucket

NJ,
Do not have scanner so will try to
describe wiring diagram.

High lim on top wired to break line voltage to burner on rise.

Thermostat wired to tt terminals on CA262 relay. (see photo)
Turns on circulators and ss terminals are wired to TT on
burner relay.

Rodgers-White 11d31-1 spdt (grey, mid back of boiler) is used as circulator cutout. Breaks on temp drop. set at lowest setting with dif closed. I assume it is so low because return water comes back room temp sometimes.

CA-666dt in tankless well (see photo with black wire disconnected) is rated for line voltage but was wired in parallel with CA262 relay ss terminals. I have not gotten it to do anything. Took it out and lubricated it. My guess is it was a low limit for tankless and is supposed to have a differential. Should close on drop and open up on reaching differential. Otherwise burner runs to high limit, I think it was acting as a permanent TT jump causing boiler to cycle between Hi Lim and Hi Lim differential regardless of heat call.


Storage tank has independent circulator controlled by aquastat in tank well.


I guess I still need a low lim switch. Is there a way to use
W-R11d31-1 spdt as lowlimit and set the differntial to shut off boiler to maintain HW without hitting HiLiM
Will it still work as circ controller or do I even need a circ cutout?

Thanks,
Fred
 
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Old 12-21-09, 12:24 PM
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Answering my own questions

I guess I still need a low lim switch.
At least in off season if I want DHW

Is there a way to use
W-R11d31-1 spdt as lowlimit and set the differntial to shut off boiler to maintain HW without hitting HiLiM
Yes

Will it still work as circ controller Not as currently wired.
Circulator is line voltage and lowlim is 24v. Can not mix on spdt

or do I even need a circ cutout? Maybe not. Since it is set so low anyway and do not seem to be at loss for DHW.

I am considering using a White-Rogers 11d18-1 for low lim.
and leave circulators wired as is.

Make sense or am I missing something?
 
 

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