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Series EC/ECT Peerless hot water/steam furnace issue

Our furnace does hot water and steam heat - one pipe system -

For some reason a valve(?) is staying open even with heat off and sending steam when water is heating, causing our radiators air vents to hiss a bit while the heat is off.

This is the first winter since the installation(2006).  We typically shut the furnace off during the day in summers to save from heating hot water when not needed.

Since we started using the furnace(for heating) this year, it has been causing the radiators to heat up

even though the furnace is set to off.

Any input would be appreciated.

I do have many pics and model information as needed


is one of the model numbers on the unit.  Hope this helps and ask away - will be glad to offer any other required info.




  • nicholas bonham-carternicholas bonham-carter Member Posts: 6,535
    edited December 2012
    Unwanted steam

    Has the steam been coming on when the hot water is made ever since the installation, or do you mean that the house is new to you?

    Is it using a coil in the boiler or an indirect? Some pictures of the boiler and piping etc. would be helpful to diagnose the problem.

    There should be some sort of aquastat which only fires the boiler enough to heat the water, when the thermostat is not calling for heat, and it seems not to be working.

    When your vents hiss, it means your main (not radiator ) vents are not doing the job, and you are paying the gas company to squeeeeeze the air out, instead of letting it escape with no resistance; and your pressure may be too high, which is another moneymaker for the gas company! Now would be the time to address all these issues, so you can start using less fuel at the start of winter instead of at the end.--NBC
  • GrandpaKirkGrandpaKirk Member Posts: 6
    edited December 2012
    only this year

    The steam isn't as much of a concern as the fact that the rads shouldn't be getting any heat when it is only calling for hotwater heat.

    A few points of fact - sorry I wasn't able to convey as much rel nfo in the first post - I will try to be a bit more clear in this reply.  including the pics.

    Oil burner (beckett)

    Have owned house for over 12 years - replaced furnace with this system in 06.

    We had the same system sans incorporated hot water prior to.  we just nixed on the electric water heater and bought this unit.

    It has all been working fine - and actually still does - other than the fact that - now - this season only - when the hot water is heating - the rads get a bit warm and some of my air vents do start hissing - and I am aware of the need to replace these - but I like to solve one issue at a time - I have had to change those air vents - since living here 3 or four times - this is the first time since 06 though - and the hiss is coming from the air vents on the rads - not the main.

    hope this helps - I do have more images - just hate to bombard with unwanted pics -

    Thanks for your time.

  • One issue at a time

    Maybe the over-pressure is a contributing factor wit your present problem, so have the tech look at it.--NBC
  • GrandpaKirkGrandpaKirk Member Posts: 6
    edited December 2012
    over pressure?

    Not sure what I said to imply over pressure - certainly haven't seen any other indications that any appears to be running over pressure - not to say it is not either - being that it would indeed explain things if it were the case.

    Our air vents - or at least the 15$ ones(they make better but the price goes higher as well), I had installed in 06, do not seem to last long - when the steam reaches them - you can tap them and they will close - - some of them - but another factor in our hissing air vents is that two of our rads are slightly askew - in the wrong direction, will be re-leveling those soon to permit proper return.

    Is there something I could look into to confirm we might have an over pressure issue? our gauge has never come close to reaching a high level - but would be glad to be enlightened if I am over looking something.

    If there is an aquastat - I will be more than glad to change it out - just feel better being prepared before I break it down - will be sure to have all new parts before hand.

    We usually keep filters/nozzles and blower gaskets on hand as well to do our yearly cleaning - we've done good so far.   Being the winter, it doesn't bother us when the rads get a little warm with the water heating, but would like to resolve this before summer comes and the hot water is also heating the house... yikes.

    Thanks for the time

  • Signs of over-pressure

    When you can hear the vents hissing, it is usually a sign of over-pressure, bad main venting , or over-size of the boiler. The air should escape silently before the pressure gets to 2 ounces. You need a good low-pressure gauge (gauge, 0-3 psi) to verify this.

    There should be an. Aqua stat on the boiler which will fire the boiler when the water cools below a certain temperature, and then cuts the burner when that temperature has been reached. When the thermostat calls for heat, then the burner will fire until steam is made, and cuts off when the pressure reaches 1.5 psi, or lower.

    Somehow your controls on the water side are not cutting the burner when hot water has been made.--NBC
  • GrandpaKirkGrandpaKirk Member Posts: 6
    Check valve?

    After going over some of the documentation I have on this unit - I see that there is a check valve between the boiler and the hot water tank within the furnace - would a bad check valve cause this issue - where heated water in the hot water supply is permitted to bleed back to the rads causing xtra heat to travel to the rads?

    Not sure if this would be important, but I did notice today that the water level was low - still on the site glass but seemingly low.   We do have an auto feed on the water.

    Another fact that might be important is the fact that our water here in NE is very hard - so not sure if this could cause a problem in the check valve or any others within the furnace - it certainly can in other points on our house.

    Would certainly love to tear this down and make it happy again - but again, I feel better have more information before hand in case I might be alerted to something I could possibly overlook.

    As far as the air vents go - I will be purchasing 12 more soon and will yet again swap them all out at once as they do tend to start going faster when others are bad.

    Thank you again for your time -

    Grandpa Kirk
  • Venting replacements

    Save your money, and check the main vents, as the good radiator vents rarely fail, unless they are doing all the system venting, (and hiss or whistle).

    What part of NE has such hard water?

    Once the system is full, it should be taking on only a few gallons a year, so calcium buildup should be minimal, except on the hot water side.--NBC
  • bill nyebill nye Member Posts: 307
    the picture

    The picture you posted shows that the Pressuretrol (little grey box with numbers and pointers on front) is set at about 8 or 9 psi. Your vents are good for 3psi max. As Dan Holohan has been quoted "Crank it down ! "

    Also check to see what temperature your hot water aquastat is set at, 160°-170°F is considered "normal" Steam does not happen until 212°
  • GrandpaKirkGrandpaKirk Member Posts: 6
    edited December 2012

    The quest for knowledge always seems to invoke so many more questions.

    To take a step back for a minute, my primary concern is why the radiators are getting a bit of heat while the hot water is being called for.  Am curious as to whether or not this would be a check valve failing of another issue.  Since it is the season for needing heat, it is not as much of a concern as it will be in a few more months.  Important still to rectify it as soon as possible.

    Now I am curious about a few other things,  the CUT OUT pressure is indeed set near 9 psi.   Could you possibly elaborate on the significance of the current setting and possible ramifications if not properly set?

    Every setting, other then the hot water temp, is what the furnace was set at when installed in June 0f 2006.  Have had no problems with anything with the unit until this season.

    Other than replacing the air vents, as they do stop working properly if they get any contamination.   To the best of my understanding, the air vents at the end of the rads are designed to permit the air to escape while the steam is filling the rads, at which point they close, or are supposed to.  Are these the ones that you mention should be good to 3 psi or?

    Our hot water is set to approx 171° F, any adjustments to the hot water thereafter is done with a blend/mix valve where the hot water feeds to the house plumbing.

    Thank you all for your time and input into my quest for knowledge.

  • Perils of high pressure

    Above 3 psi=shorter vent life span.

    Above 2 psi=superheated radiators with discomfort, and wasted fuel.

    Above 6 ounces some fuel waste, but comfortable.--NBC
  • GrandpaKirkGrandpaKirk Member Posts: 6
    High pressure woes

    So basically, I could conceivably set that cutout to .5 - all the way down - and everything would be fully functional and safe?

    BTW - We're in CT.  The town we live in gets water from a few different wells and the calcium build up we experience - let's just say is very nasty...   Would the calcium travel with the steam and damage the air vents as bad as the water could?

    Another query in regards to changing the pressure - could the high pressure - after 6 years be the culprit for the rads getting heat during water heating? Or should I still consider the possibility of a bad check valve that might not be staying closed when it should?
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