Can Domestic Hot Water Function on Peerless Boiler (Steam Heat) be Disabled


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Old 11-05-11, 09:05 AM
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Can Domestic Hot Water Function on Peerless Boiler (Steam Heat) be Disabled

Due to a death in the family, I'm responsible for a vacant house in NY which is over 200 miles away. The house has steam heat from a Peerless boiler. Domestic hot water is supplied from this same boiler (no external tank). I'd like to minimally heat the house over the winter without having the boiler kick on unnecessarily to maintain unneeded hot water.

Is there an easy way to disable unneeded calls for hot water while allowing the heat to function normally? I've looked at several articles on the Internet which discuss HI, LO & DIFF settings for an Aquastat but this Aquastat has a single external wheel for setting a temperature (Low of 90 degrees, currently at 140 degrees). I'm not sure exactly what function this wheel is setting.

Unfortunately I don't have the Aquastat make or model number and would have to drive to NY to get it. In NY, I don't have ready access to the Internet. From this limited information, can anyone tell me what type of Aquastat a boiler configuration such as this one would use, which setpoint is being controlled by the external wheel and how (if possible) I can disable calls for domestic hot water without affecting calls for building heat?

Thanks!
 
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Old 11-05-11, 09:28 AM
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Don't ask for much, do you?

On a steam boiler the aquastat is usually wired in parallel with the pressuretrol. Disconnect one wire (there should only be two) from the aquastat and insulate it.
 
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Old 11-05-11, 10:59 AM
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So the aquastat keeps the water hot enough to make the domestic and the pressuretrol creates the steam on a call for heat?
 
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Old 11-05-11, 11:11 AM
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That's the usual arrangement. Some boilers might have a different control scenario.
 
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Old 11-05-11, 11:35 AM
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What would happen if the external temperature wheel was changed to drop the temperature (of something) from 140 to 90 degrees?
 
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Old 11-05-11, 11:45 AM
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I also recall reading that the HI function of the Aquastat serves as a cut-off temperature of the water in the boiler when it's calling for heat - the HI setting is not related to the domestic hot water function. Would detaching one of the two wires from the Aquastat also disable a safety feature? Thanks!
 
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Old 11-05-11, 04:02 PM
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What would happen if the external temperature wheel was changed to drop the temperature (of something) from 140 to 90 degrees?
Then the boiler would maintain a temperature of approximately 90 degrees instead of 140 degrees. This might be a good idea on a cast iron sectional boiler that has always been kept warm. Sometimes cast iron sectionals will leak at the sections when allowed to go completely cold. It will take more fuel to keep a warm boiler although 90 degrees will be less fuel than would 140 degrees.


I also recall reading that the HI function of the Aquastat serves as a cut-off temperature of the water in the boiler when it's calling for heat - the HI setting is not related to the domestic hot water function. Would detaching one of the two wires from the Aquastat also disable a safety feature?
Not in a steam boiler.
 
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Old 11-05-11, 07:24 PM
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If a boiler appears to leak when cold it [could also be] leaking when hot. [Except that when hot, the] water evaporates [quickly, and is often] not detected [as a leak].

All boilers can be cold start to save lots of fuel[, [citation needed] and] that's why DHW coil direct to taps is a very expensive way to produce hot water for washing dishes [or anything!].

[NJT edit - Let's also try to keep in mind that this is a STEAM system!]
 

Last edited by NJT; 11-05-11 at 09:14 PM. Reason: readability
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Old 11-05-11, 09:28 PM
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what type of Aquastat a boiler configuration such as this one would use, which setpoint is being controlled by the external wheel and how (if possible) I can disable calls for domestic hot water without affecting calls for building heat?
Robert, the aquastat is probably a SINGLE aquastat only. Most likely one like this:


image courtesy honeywell.com

and that setting would likely be around 140 or so. There is probably another adjustment internally for what is called a 'differential' temperature, but if you are disconnecting it, then you don't need to be concerned with that at all.

That aquastat 'probably' has two wires on it. Usually Furd's suggestion of removing just the one wire and taping it up is sufficient to stop the indirect from heating.

You do need to give us a bit more info in order to get a concrete answer though...
 
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Old 11-05-11, 09:30 PM
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If the home will be vacant over the winter a freeze alarm would be a wise investment. Google for more info. These are often combined with water alarms also (sensor on the floor of the basement usually). They will telephone you if there's a problem.

something to look into...
 
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Old 11-06-11, 04:29 AM
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I have some of the installation material available (unfortunately nothing dealing with the Aquastat) but maybe it will help.

The Installation, Operation & Maintenance Manual is for "Series WBV/WV Oil Burners". The unit was new in October or November 2005, so it's not ancient. The warranty page title is "Residential Cast Iron Boilers/Parts Limited Warranty Effective February 18, 2005", so it looks like it's a cast iron unit. It's definitely oil fired.

Going a bit further out on a limb, my guess would be that the boiler is a model WBV-03-085 or WBV-03-110. (The "Boiler Ratings" table shows 8 WBV and WV models. Only 4 of these show "BTU/Hr Steam" ratings so my belief is that the others are water boilers. The other 2 use nozzles of 1.00 and 1.10 with Riello and I'm fairly certain that the technician used a nozzle which was under 1.00.

The installation manual for the burner is titled "Riello Burners Model F3 & F5 Installation Manual - Reillo 40 Series Residential Oil Burners". The F5 seems to be the appropriate model for all boilers which show a "BTU/Hr Steam" rating.
 
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Old 11-06-11, 08:29 AM
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Since you have the manual,

http://www.peerlessboilers.com/Deskt...hod=attachment

take a look at the diagram on page 11 , figures 4.5 and 4.6

Chances are very good that your boiler will be wired much as this shows.

Look at the 'primary control' on the left side, find the T-T terminals on that control.
Notice that it shows there two sets of wires on these terminals. One set comes from the thermostat, the other from the operating control for the water aquastat. One of the wires from the water aquastat is the one you need to disconnect and insulate.
 
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Old 11-09-11, 09:12 AM
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Thanks everyone. I disconnected and insulated one of the Aquastat wires and it seems to have done the trick. (I had seen the diagrams mentioned by NJ Trooper but the label "Operating control for steam w/ tankless heater only" left me unsure as to exactly which control the caption referred.)

Again, thanks to all. I appreciate your help.
 
 

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