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New to boilers - what do I do?

I all.  I found this site, and it is awesome.  My wife and I just bought our first home.  Built in the fifties, it has hydronic heating with a Weil McLain boiler with a circulator.  System is a single loop monoflow tee design, with all baseboard heaters (no in-floor).  System appears to be installed professionally, and I have not found anything wrong according the little bit I've learned about boiler systems and piping so far.

House is 1-1/2 story, and about 1500 sq ft on the main floor.  Boiler is rated at 140,000 BTU/hr.  Initially, we were having issues with the upper level not heating up (the baseboards wouldn't get hot).  I bled some (quite a bit, actually) air out of both rooms, and that solved the problem.

Now, what do I need to do to take care of my boiler and system?  The water temp is set at 140, and when running, there is about 18 psi in the system.  There is also a red line at about 20 psi, so it's close.  A cold water line enters the boiler water system, and it goes through a hand valve, a back flow preventer, and a pressure regulator.  The valve is currently off, and I assume that it is supposed to stay off?

Do I need to regularly "top off" the water in the system, and if so, do I go by the pressure gauge as to when to do this?  Do I need to periodically drain and refill the system?  What about chemicals in the water - does it need to be treated?  There is a ton of info about designing and installing systems on this site, and it is all excellent, but right now I'm looking for more on how to take care of they system.  Thanks in advance!


  • CMadatMe
    CMadatMe Member Posts: 3,086
    Welcome to the Site

    Normal operation would not have the water set to 140 degrees. This would mean that you return water temp would be 120 degrees which is not good for a cast iron boiler. Minimum return temp should be 140 not the supply temp. As far as your feed goes. We do not have to feed hot water boilers any longer. The feed valves today make sure that the system maintains the 12PSI it is suppose to be operating at automatically. Check the brand and model number of that feed valve and make sure it is a Watts S1156 or B&G FB38. These are the most common.
    "The bitter taste of a poor installation remains much longer than the sweet taste of the lowest price."
  • Steve_R
    Steve_R Member Posts: 5
    Which Weil McLain is it

    If it's an Ultra, you can run lower temps. Baseboard manufacturers publish tables showing what BTU/H per foot you get from a baseboard at whatever temp usually ranging from 150 - 220 degrees. Do you know if there is an outdoor reset that may be lowering the operating temp? Systems here are usually set at 180 on design day
  • BrotherPig
    BrotherPig Member Posts: 2
    edited December 2009
    Thanks for the replies!

    I've got some more information here.

    The water temp is run by a manual thermostat that is connected to the boiler discharge water pipe, and it is currently set to 140 deg.  I do not have any issues with keeping the house warm.

    The boiler is Weil-McLain CG-5-PIDN natural gas boiler.  I said earlier that it was 140,000BTU, but that is the input BTU rating - heating capacity it 117,000BTU.

    It has a TACO cartridge circulator, 1/25 hp.

    There is no outdoor reset on the system.

    I also said before that it appears to be installed professionally (that's coming from me, which although I am handy around the house and mechanically inclined, I have no experience with hot water heating systems), but I will say that at some point the owners must have been having issues with keeping the upstairs warm, because there is an in-wall coil with fan installed, presumably to get more heat into the bedroom.  The hot water comes from a tee that is directly off from the main boiler discharge pipe, and returns back at the main boiler return pipe.  They simply used soft copper pipe to run up the chimney chase to the second floor.  The tee that comes off for the supply is not a monoflo tee.  We do not have any issues keeping the upstairs comfortable for us, but it does stay cooler than the rest of the house because 1) it is closed off from the thermostat with the stairway door, and 2) the heat loss is greater (1.5 story with not the greatest insulation).  But, I don't have any complaints with temp.  (that is since I bled air out of the upstairs radiators)

    We are able to easily keep the house at 65, and the upstairs stays at 60 - 65.


    As far as the water temp goes, I see that it may be too low for my boiler.  But right now the boiler runs infrequent enough, that the water temp will dip to around 100 deg between cycles.  If I do increase the water temp, I don't think it will stay that hot.


    Thanks for the input.  I'm trying to learn as much as I can.  Just so everyone knows, I do plan on having a boiler person come out to just see and inspect the system.  Hopefully I'll get more info then.  But that won't happen until after the holidays, and I'm of the mildly impatient type :)


    Thanks again!



    EDIT: Sorry, forgot about the supply valves!

    There is a 1/2" copper supply line, then a 1/2" hand valve (just a regular hand valve), followed by a 1/2" WATTS 9D-M3 Backflow Preventer, followed by an ITT BELL & GOSSETT B-38 Pressure Reducer.  The tag says it is set at 12 lbs, but who knows if anyone has changed that.
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