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    t56tr's Avatar
    t56tr Posts: 25, Reputation: 1
    New Member
     
    #1

    Sep 2, 2009, 09:24 PM
    Water temp in boiler.
    Hello,

    I have a home in upstate NY that was built in 1929 - it is two story, brick, 2200 sq ft. 4 bed, 2.5 bath, third flr walk up attic unfinished. The house has no insulation, just some old deteriorated brown cardboard behind the brick. Original wood windows, but someone did install some nice storms within the last few years.

    It has the original hot water heat system, which consists of cast iron radiators in every room that are fed by 1" steel pipe.

    In the basement, there are massive 3-4 inch cast iron pipes that run around the perimiter of the foundation, where every radiator drops into. It looks as if there is one large (3-4") feed and then another 3-4" return.

    All of this ends up at a peerless mc-05 forced water natural gas boiler that is dated/installed 1991.

    The installer fitted the peerless in by using all 1 1/4 copper connected up to the orignal cast stuff. The install looks professional I guess.

    Anyway, when I had the home inspection done (prior to purchase last year), which was performed by a reputable home inspector, he commented that the boiler looked kind of small for the house.......

    My concern is that no matter what the outside temp is, wether its 40 or 5 degrees etc, when the thermostat kicks the boiler on, it seems to run and run and run before it brings the house up a couple of degrees. For example thermostat set to 66, temp drops to 64, turns on boiler.

    When I look at the gauge on the side of the boiler, the pressure is usually about 10lbs, and the water temp never goes over 135 deg (assuming the gauge is accurate).

    The radiators in the house, especially the second floor, barely even feel warm when the boiler is running. Sometimes they even feel cold. Heck, the main 4" cast feeds in the basement don't even really get hot, but just warm.

    Someone told me that the 135 operating temp was too low. Is that true? Shouldn't the radiators be getting hot? If so how do I raise the temp? Or was the home inspector right?

    Here's the kicker...

    In the winter the heat seems to work fine. Even on extremely cold nights (5 degrees) the house can maintain 70 degrees (never set the stat any higher so I don't know how much more it would go). And, despite the boiler running and running during warm ups, and the needles on my gas meter going around at mach 10 my gas bill seems extremely reasonable for the coldest months of the winter (maybe 375 for gas last feb - heat and h.w.) - I heat h.w with gas, a 20 yr old 40 gal a.o. smith unit.

    Finally, one morning we had no heat on a zero degree day so I called the sticker on the boiler from the heating compant that installed it. They came right over because the temp inside was already 45 deg. Turns out the thermo-couple took a crap. So I asked the tech about all of the above and asked him to check it. He said everything was fine nothing to worry about (oh and $350 for the thermo vist).

    So does this scenario sound normal? Should the boiler seem to be working so hard?

    PS the house is all one zone. The basement is part of that zone, it has antique baseboard around half of it (tapped into the 4" at some time). The basement heat is on when ever the house heat is on (which is OK, laundry is down there etc).

    The only other info I have is I bled all od the rads (they were fine), boiler has a honeywell aquastat L18148e, taco circ, and a 12lb exp tank.

    Any insight would be appreciated
    hvac1000's Avatar
    hvac1000 Posts: 14,540, Reputation: 435
    Heating & Air Conditioning Expert
     
    #2

    Sep 3, 2009, 05:19 AM
    First of all someone did you a favor if you can heat that 2,200 sq.ft. home with 135 degree water. Also your utility bill is cheap for heating a old brick house of 2.200 sq.ft.

    If you were to raise the temperature up to lets say 165 degrees your utility bill would be much higher due to the % of loss up the stack due to inefficiency of the boiler.

    It seems whoever installed and adjusted your boiler new what they were doing.

    Now a line by line explanation.

    All of this ends up at a peerless mc-05 forced water natural gas boiler that is dated/installed 1991

    The boiler is a older unit but boilers are designed to last 50 years or so. I would not consider replacing it unless it fails completely before that time.

    My concern is that no matter what the outside temp is, wether its 40 or 5 degrees etc, when the thermostat kicks the boiler on, it seems to run and run and run before it brings the house up a couple of degrees. For example thermostat set to 66, temp drops to 64, turns on boiler.

    It is operating as designed and a 2 degree drop to activate the boiler is normal in your situation. Any closer differential and the boiler would be starting and stoping all the time causing your utility bills to be higher.

    Someone told me that the 135 operating temp was too low. Is that true? Shouldnt the radiators be getting hot? If so how do I raise the temp? Or was the home inspector right?

    Who ever told you this is not taking into consideration your homes design criteria and the reason behind the 135 degree temp. It is working so leave it alone as long as it is not causing condensation on the boiler sections. If it was causing that the service man would have told you that they would have to raise the temperature.


    Finally, one morning we had no heat on a zero degree day so I called the sticker on the boiler from the heating compant that installed it. They came right over because the temp inside was already 45 deg. Turns out the thermo-couple took a crap. So I asked the tech about all of the above and asked him to check it. He said everything was fine nothing to worry about (oh and $350 for the thermo vist).

    In NY area 350.00 for a T-Couple replacement is probably normal. Everything in NY is expensive.


    So does this scenario sound normal? Should the boiler seem to be working so hard?

    Everything seems normal and your boiler is coasting since it is NOT working hard. Working hard for a boiler is running 180-190 degree water.

    It seems you system is just fine. You will have to occasional part to replace but other than that the system should last a long time.

    NOTE: There are more efficient boilers available BUT with the type of structure you are heating your utility bills are not bad enough to replace it. A new boiler in your area is probably 8,000.00 to 10,000.00 easy and your energy savings from a new boiler would not make up the difference plus the new high eficiency boilers need at least one expensive service call per year just to clean it and that is something you CANNOT due to the nature of the new beasts.
    t56tr's Avatar
    t56tr Posts: 25, Reputation: 1
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    #3

    Sep 3, 2009, 06:18 AM
    Thanks for the reply. That is what I figured, and also that is just about what everyone has told me. If something isn't broke don't fix it.

    I was just curious because when I visit other peoples homes in the area, there is usually all of this clinking clunking banging and hissing noise when the heat is coming up, followed by rooms that feel like a sauna and/or radiators that are too hot to even get near.

    My house I am constantly running to the basement to see if the boiler is still running because there's never any noise or hot rads etc.

    I used to rent a 700 sq ft apt that had gas forced air and the gas bill there was 200 in the coldest months, so yes I do feel that this nat grid bill is fine.

    It would be nice to throw a pair of damp gloves on or near a rad though and have them warm and dry after a few hours, but I guess that's a trade off.

    Oh, one thing, I had the boiler shut off all summer due to a couple of small renovations. When I bled the system and fired it up all seemed well. Then I noticed the temp gauge was heading for 190 and the big cast pipes above the were definitaly feeling hot, however nothing else was. I quickly realized the taco was not working. I listened to it through a large screw driver and I could here it humming but not whirling. I banged it with the handle of the screw driver and it started whirling, then the boiler temp went to its 130's and the house hit the 72 I put the stat at to test it (from 70 indoor temp).

    Is that normal for a unit that sat all summer drained? Also, just for a learning exp, what if that taco locked up in the middle of the night when everyone is asleep? Would the boiler temp skyrocket with no circ, or is there some safety mech that kicks in?
    hvac1000's Avatar
    hvac1000 Posts: 14,540, Reputation: 435
    Heating & Air Conditioning Expert
     
    #4

    Sep 3, 2009, 07:24 AM
    There are safety controls built into the system and part of that safety controls job is to lock it out at about 190 to 200 but the temp might be different depending upon how it was adjusted.

    I would pick up a NEW pump and gaskets of the same model and voltage to be ready if the old one goes out. Yours might have just been stuck but new ones are available on Ebay for a sweet price. If it was not for Grundfos giving me all the pumps I need for my classes at the university I would be buying them off Ebay since the price can be a lot better than wholesale. Now when it comes to changing that pump you might be better off calling for help unless you have isloation valves before and after the pump.

    It sounds like you have a nice and economical system that serves you well so make sure the maintaince is done when necessary and enjoy the heat.
    t56tr's Avatar
    t56tr Posts: 25, Reputation: 1
    New Member
     
    #5

    Sep 7, 2009, 08:24 PM

    All of the pipes in the basement, the large 4 inch and all off the 1 inch feeds used to be wrapped in asbestos. All of it was removed at some time except for where the pipes poke up into the outside walls where it is still visible.

    Should all of those pipes be re-wrapped in something, or is that a waste? It seems like it could get expensive... lots of iron to wrap.
    hvac1000's Avatar
    hvac1000 Posts: 14,540, Reputation: 435
    Heating & Air Conditioning Expert
     
    #6

    Sep 7, 2009, 09:09 PM
    Wrapping the pipes will mean less heat loss. The pipes are probably heating the basement right now since they are not insulated. You can actually wrap those pipes with fiberglass wall insulation that comes on a roll. There is a calculation that can be done but it is a real pain to do and it involves a bunch of measurements. Look at it this way. If the basement is not to hot do not worry about it. If you ever have some spare $$$ and time have at it.

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