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steam in the summer!

Bearno Member Posts: 4
I have 4 years old Benham (Gas)steam boiler and Bernham tank.

when thank asking for hot water boiler works to the point that generats steam which we don't need in summer time.

I have replace the Honeywell Presuretrol ( L404F367)and the also Honeywell Board R8845U. Both unites are New.

I also took of the pigtail pipe and the elbow that attaches to presuretrol clean both they are totaly open.

I set Main presur on 1 and the differential to 1.5 for steam.

the thermostat on tank is set on 115 and the differential on almost 10.

the room thermostat is set on almost to 60 .

Problem: when some one talkin show the boilere kicks and it runs to the point that the radiators in the house start making hissing noise and warming up.

Any idea to solve the problem?


  • Jamie Hall
    Jamie Hall Member Posts: 22,941
    Is this thing

    set up as an indirect with circulation?  That is, is there a circulator taking hot water from the boiler, running it through a heat exchanger in the tank, and back to the boiler?  If so, something is amiss with the control on that circulator -- it should only run when the tank needs heat -- and there should also be an aquastat on that line, which turns the boiler's burner off when the circulating water is hot enough -- say 160 or so.

    Or... is the tank simply storing hot water which is being created by the a domestic hot water coil in the boiler?  If so, again there should be an aquastat on the system which shuts the boiler off when the boiler water is hot enough.

    Or at least that' the way I'd have it set up...

    But it's basically a control problem.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • Bearno
    Bearno Member Posts: 4
    Steam in summer!

    The Tank just storing water. I checked the aquastat in the tank it works properly.

    the boiler works more than it suppose too. it shuts-off eventually , but its too late after generating steam.
  • Jamie Hall
    Jamie Hall Member Posts: 22,941

    you are drawing hot water from your tank faster than your boiler is capable of making it.  Therefore the aquastat on the tank keeps calling for heat.  What is needed is a control on the boiler itself to shut it off when the boiler water reaches a reasonable high temperature, assuming that the thermostat isn't calling for heat.

    Either that control is missing, or not set properly.

    It's worth noting that you also have a capacity problem here -- you are drawing hot water faster than your system can make it.  Get the one problem fixed, and you may discover that you don't have enough hot water...
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • Bearno
    Bearno Member Posts: 4
    Steam in summer!

    What you are saying makes sense but this is a new problem which we didn't have since we install the system. system is 4 years old, thermostat is not calling for heat there is no temperatur contral on the boiler.

    I pulled the aquastat out of the Tank and insert in cold water it starts the boiler while boiler was running I took it out of cold water and insert it in almost boiling water it shut the boiler off. I spoke with people in Burnham they were not helpful becase I'm not license contractor!
  • Eric_32
    Eric_32 Member Posts: 267
    edited June 2014
    The aquastat

    The aquastat in the indirect heater controls the temp in that tank.

    It needs to also have an aquasat installed in the boiler (below the water line) which takes the boiler water temp and will control the burner by breaking the end switch to the burner. Turning the burner on and off before making steam. It is not something I believe the factory would include on the boiler.

    Something like a Burnham 100189-01 High Limit Aquastat

    The pressure trol CAN NOT control this... it operates off pressure. If you have any pressure it ran it too long.

    You need an additional control ON the boiler which operates off temp. for hot water.
  • JStar
    JStar Member Posts: 2,752

    You should also set the tank temperature above at 140F to kill off any bacteria and the chance of Legionella. 115F is a breeding ground for harmful water pests.
  • ChrisJ
    ChrisJ Member Posts: 15,484

    I originally had mine set around 120F until I read several reports regarding Legionella and decided to increase it to 140-145F.

    I wonder if it's a concern as I have city water that definitely has chlorine in it, but I figured better safe than sorry.
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • Steamhead
    Steamhead Member Posts: 16,732
    Here's one we installed

    which is controlled the same way yours should be:

    All Steamed Up, Inc.
    Towson, MD, USA
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
  • RobG
    RobG Member Posts: 1,850

    Can you post some photos of your boiler and indirect water heater? That would really help in figuring out what is going on.