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Steam Heat Saves The Day

Well, we are now on day 4 with no power due to an outrageous ice storm. Expected restoration date is Jan 3. In the middle of the storm, at 3am, when it was obvious power was going to be lost, we had about 1 1/2" of ice of the ground at that point, I started thinking. A quick middle of the night trip to Meijer to get a 900w Diehard jump start unit, and a little rewiring on the boiler, we have maintained heat the entire time. Since Saturday night the unit has only used 13% of it's power so it should last about a month on a single charge.

I have the generator running to power the house now but still left the boiler on battery power. No sense in using the amps to power the transformer if it's not needed. I would highly recomend all you steam heads to look into rigging up an emergency 12 volt solution to run your system. I was lucky to be able to get it done the way I did. Once you loose power across the entire grid and no stores are open, you'll be glad you have heat and no need for parts from Lowes. Lights and electricity are luxuries, heat is not.


  • Hap_Hazzard
    Hap_Hazzard Member Posts: 2,398
    I still think a backup generator is the way to go.

    Freakish weather is the new normal, and our power grid isn't up to it anymore, but at least the gas supply never goes out (knock wood).
    Just another DIYer | King of Prussia, PA
    1983(?) Peerless G-561-W-S | 3" drop header, CG400-1090, VXT-24
  • fixitguy
    fixitguy Member Posts: 83
    Bad storms can always be expected in this part of the world

    We lost power for a week 2 years ago. I love millivolt systems. Fortunatally the dead men installed a lot of them and they still survive. No one here likes to talk about converting, but it is possible. The 24 volt system is AC not DC, but in a pinch I have made 24v gas valves work with 3 - 9 volt batteries snapped together. They dont last long though. One day closer to spring.
  • MDNLansing
    MDNLansing Member Posts: 297
    DC Gas Velves

    My valve is 24 vac or 12 vdc. The system used to be 24 vac, I have now swapped the transformer out of a DC one and hardwired the battery backup. A single charge of a 900w jump start unit will cycle the valve for about a month being that it only uses .18 amps.
  • Hap_Hazzard
    Hap_Hazzard Member Posts: 2,398

    Another possibility would be to connect the transformer to a UPS (uninterruptible power supply, not the company with the brown trucks).

    I'm not sure how long this would stay up; these things are designed for much higher loads, so I'd think they'd last for weeks, but I haven't actually tried it.
    Just another DIYer | King of Prussia, PA
    1983(?) Peerless G-561-W-S | 3" drop header, CG400-1090, VXT-24
  • rmoore007ri
    rmoore007ri Member Posts: 45
    edited December 2013
    backup power

    I purchased the largest jump pack Sears sells which has a built in inverter for 115 VAC. I then spliced in a transfer switch beside my emergency shutofff switch at the top of the basement stairs. This lets me patch power into the furnace safely. (go to ebay and search using EZ GENERATOR SWITCH)

    This has only to run the damper and hold the gas valve open. My measurements indicate this would run our steam system for 36+ hours.
  • Toymotorhead
    Toymotorhead Member Posts: 54
    edited December 2013
    12Vdc TO 24VAC UPS.

    I have a large computer UPS that I could use to power my steam boiler in in a blackout if necessary, I also have a large portable generator. But I have been on the lookout for a much more elegant solution to the problem.

    Converting 12VDC to 120VAC and then stepping it back down to 24VAC is an extra conversion step. Conversion losses kill efficiency, and when you are running on batteries, efficiency is everything. Even if both of your conversion steps are 85% efficient. You have already lost 30% of your power stored in your battery backup, before you even start.

    I did some reasarch and found this:

    Its a 12VDC to 24VAC inverter designed to run security systems. But you notice it is in the familiar 40VA capacity of the HVAC world.

    They also make a larger capacity one for more money.

    I have not had the available spare funds to purchase one, or do any testing. But I figured I would put it out here for you crazy kids to look at. Your mileage may vary.

    During the blizzard last spring (Nemo?) we lost power overnight, and through the next day. I was amazed how long I could keep the house livable having run the boiler off the generator to the point where the system went off on pressure (rare in my case) The house would freewheel for a few hours on a few thousand pounds of 200` cast iron. I only made 3 generator runs all day to keep the house livable. (livable not comfortable)


    If you can't be good, at least be good at it.
  • Jean-David Beyer
    Jean-David Beyer Member Posts: 2,666
    edited December 2013
    I'd think they'd last for weeks

    I would not count on that. The nominal rating of my APC Smart-UPS units is the amount they can put out at about 50% of their rated load. As you lower the load, the run time gets longer, but not in a linear fashion. At low loads, the losses in the UPS become the dominant factor.

    For example, I have a 620 watt model that became spare. I use larger UPS models on my two computers. The 620 watt one was for my third computer that has been given away.

    When I got Verizon FiOS data and telephone connection (it will also do TV, but I do not use that), I plugged the FiOS box that converts fiber optic signals to telephone pairs, ethernet, and video into that UPS. It has a little UPS inside it, but if power fails, it shuts off the internet and the video.

    Now sometimes I get long power failures (say a day or more, once 4 days, and during Sandy, 6 1/2 days). The FiOS box draws very little power, but it petered out in about 8 hours. My guess is that no matter how big a Smart-UPS you get, you are unlikely to get a lot more than that, though I have not tested that. I do get about 2 hours running my main computer with a 2200 VA model. My machine runs a little over 200 watts including a router, cheap speakers, and an inkjet type printer (when the batteries are new; about 1/2 that when they are three years old, at which point I generally order new batteries).

    Some of the Smart-UPS units come with auxiliary batteries for longer run times, but at some point you have to give up and run a generator.

    Here is a page from APC that would help you select one of their Smart-UPS models based on the power required and the run-time desired.
  • MDNLansing
    MDNLansing Member Posts: 297
    The Other 70 Percent

    UPS units will certainly work, but they are designed to discharge high amps for short periods. They will discharge far more amps then being used to maintain battery life. Slow drawn out battery discharges make them fail faster, and no manufacturer wants you to have to replace a battery in their unit. They know you'll probably by a new unit and possibly switch brands. So, they design the units for optimal battery life, not runtime. This means running a low voltage at a trickle every once in a while, like a boiler would do, will cause the UPS to discharge power on it's own faster than what you are actually using. If you unplug a UPS, and let it sit with nothing attached, it will drain itself in about a day.

    To obtain the most efficient use, meaning longest runtime, you need to minimize the conversions and match the voltage. I'm using a 12 volt power source, on a 12 volt load. I connected this battery at 3 am Sunday, and still have 70% charge left as of this evening. It was only at 90% when I started using it. These jump start units have tons of amps, designed for cranking, and no logic to discharge the battery faster than what you are drawing. When I say this thing will run for at least a month on a single charge, I'm serious, it will.

    We are running a generator that I wired into the house, but I still run the furnace on the battery. For starters, it lets me shutdown the generator at night at still have heat.This saves a ton of fuel. Also, in the beginning of the outage, the generator was limited. With the grid down you can't get gasoline until the gas station is running on standby power. Believe it or not, very few stations have generators large enough to remain open while running on them. Most places here were closed for the first day. You also have to consider generator failure. They do break. The battery I'm running is solid state and has no moving parts. If it has power, it will discharge.

    So in a nut shell, I'm still a fan of running the boiler on battery. Even with a generator. I've lived through the usefulness of this thing and seen all the times the boiler would have been down without it. With single digit temps, I don't want it off for even a few hours. I would strongly suggest replacing your valve with a 12 vdc model when it comes time to swap it. If you want to prepare for things like this, do it now, otherwise wait until it breaks and needs replacing anyway. There is certainly no disadvantage to buying a 12 vdc valve instead of a 24 vac valve.
  • Binnacle
    Binnacle Member Posts: 126
    Millivolt / Thermopile way to go for gas-fired

    Another plug for older-is-better.  Have a Honeywell Thermopile millivolt system installed in 1961 and was the only one on the block with heat for ten days after Hurricane Sandy

    The idea that these controls are obsolete is ridiculous.  I happily pay $3 a month (if it's that much) to run the pilot and thermopile.

    Probably not worth replacing a "modern" control with millivolt, but if you have one keep it!

    (And keep your old mechanical thermostat in a drawer if you decide to install a fancy new Nest or Visionpro--not much use when the lights go out.)
  • ChrisJ
    ChrisJ Member Posts: 11,978

    I believe the reason the thermopile / millivolt systems are no longer made is due to safer gas valves being used.  I'm sure a pro who knows could comment as I'm going off of memory.  Also not sure if modern probe style LWCO are compatible with them.

    I believe Visionpro thermostats can work fine with millivolt systems as they can and usually do run off of internal batteries.  Mine did until recently when I wanted it lit 24 / 7.

    As mentioned in another thread in the main section I came up with a way to use a small 12V to 120V inverter to run my system off of my car.  It's been a while but I believe I can run for 5 days during a cold week without needing to start the car.  We do have a generator but I'd rather only run it to cool the fridges and freezers down occasionally if need be and to run the power vented water heater.

    I would definitely say steam heat is preferably during power outages regardless of the type.  No pumps to run and no blowers to run makes it very easy to get by with little power.  Have to wonder if it would be easy and cheap to setup some kind of solar powered system for it?
    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
  • MDNLansing
    MDNLansing Member Posts: 297
    Solar Kits

    Solar kits are easily found and work great. I have a panel mounted on a flat roof backing up the house wired smoke and CO detectors. However, I will be revisiting this as well as the 2 inches of ice we got covered them and rendered them useless. I'm not sure if they are damaged or not because none of the ice has melted. It's possible they stopped working because the ice broke them, but I am suspecting they just don't absorb solar rays when covered in that much ice. You learn a lot when your emergency backup systems are put into action. Far more than when designing, installing, and testing that's for sure.
  • Henry
    Henry Member Posts: 988
    Ice storms

    We had 21 days of no power in the great ice storm of January 1998. While I was at the Natural Gas Technologies Center, we were tasked by the president of the gas utility to find the solutions for a major power outage. We looked at everything and event tested everything including solar panels and generators. I wrote a good part of the report. The finding was that a 12 Kw natural gas generator was the most viable solution. You don't buy a generator from a big box. The ones that say 9000 watts etc are not certified to any standard. You may get 9000 watts for 10 seconds. You have to look at the commercial units that mention continuous and standby power.
  • ChrisJ
    ChrisJ Member Posts: 11,978

    I always recommend friends buy NG or LP generators as they will run fine after sitting for years and you know people won't maintain them.

    I have an early 90s Coleman 8HP generator that I think is rated 4Kw.   It will produce that output continuously but my complaint is even with a  heavy load it outputs in the high 120s.  With low load I see 130-132V and I've found no way to reduce this.  The output is almost dead on 60Hz the entire time.  Probably the worst part is you need ear protection if you're standing near it.  Its LOUD to say the least but has been very reliable especially for the cost.
    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
  • Dean_7
    Dean_7 Member Posts: 192
    edited December 2013

    I haven't posted here in a while not since the boiler failed a couple of years ago. But I live in Michigan too. About ten years ago I bought a 7500 watt portable gasoline generator (converted to run on natural gas and propane) and a 10 circuit transfer switch thinking I might have to use it occasionally. My wife thought I was nuts and we would never use it. We have used it 14 times at last count 3 in the last 11 months. The power outages seem to be much more frequent and last longer each time. I am now considering upgrading to whole house standby generator. Henry and Chris are right .
  • MDNLansing
    MDNLansing Member Posts: 297
    Whole House

    A whole house generator is certainly the best option. When we moved into this house I had an outdoor load center installed to cover this. I never installed a large hole house unit, mostly because I just never got around to it. When it became evident our outage was going to last at least a week, I added a 40 amp twist lock to the load center and hooked up the portable 6500 watt unit I have. Every appliance in my house is natural gas so the 6500 actually worked just fine. We were careful not to waste electricity, but never tripped the circuit once. It worked quite well. I will be adding a larger NG/LP unit this summer, but the portable can work if installed properly.
  • MDNLansing
    MDNLansing Member Posts: 297
    Transfer Conditioner

    They make power conditioning transfer switches to help with this. They use a small battery bank to ensure clean power output. Genny charges the batteries, batteries invert and power the house. My portable has this feature built in, but you can buy external units to work with any generator. You can however get a nice Genertac whole house unit for around 3 grand, not a bad price when you consider a portable is almost a thousand, plus another 600 - 800 for a conditioned transfer switch.

    No matter what, make sure everything is installed by an electrician, or yourself knowing exactly how to do it. There were several linemen around here zapped because the generators had energized the power line to the pole, You have to ensure you isolate the two and make it impossible for the generator and main breakers to be on at the same time. Most manufactures of outdoor load panels have lockout plates for this specific purpose. If using a good transfer switch, it will do this automatically.
  • Larry_52
    Larry_52 Member Posts: 181
    Military generator

    I bought a military mep002a diesel gen a while back. Lists at 5000w but really is a 7000w unit. Basically an over built unit that can go through 10000 hours of continuous use before any hard maintenance is needed. Best part is it will burn home heating fuel, so use you oil tank as a supply and you can run for months with heat and electric. The diesel gen has a large filter system that can handle the crap that come out of your tank. I ran through Sandy for two weeks straight only burning 19 gallons of fuel. The gen is not for the faint as it weighs in at a 1000lbs. you can find them at Was able to pick up mine for 800 bucks but had to replace injection pump.
  • Ray_Frechette
    Ray_Frechette Member Posts: 25
    Regarding deep cycle batteries

    While amp hr draw may be low, realize that if you are down to 87% capacity after 3 days that does not mean you will be able to run it 30 days to 0 % Capacity.  At least not if you want to keep that battery for more than a few uses...

    Deep Cycle Batteries should not be run down below 50% Capacity and you would do well to not run it below 60% Capacity. ''And to add further injury it is best to recharge them daily.

    You see as the battery discharges the sulphuric acid converts to distilled water and the sulphure transforms to lead sulphate on the plates.  The Lead sulphate is initially aqueous and gell like but leave it alone for a while and it will crystalize.  If you recharge within 24 hrs the lead sulphate converts back to sulphuric acid and no damage is done.  Left to crystalize it will nto convert again. And besides having less sulphuric acid in your battery the crystals insulate the lead plate  and reduces plate exposure. 

    At that point all you can do is apply an equalization charge to the battery to have some serious bubbling going on to blast the crystals off the plates to restore plate surface area.  While this helps, restore capacity somewhat and equalizes voltage potential across the plates those crystals settle to the bottom of the battery case.  Once enough of them settle the surface of them will come in contact with the plate bottoms and short them out.

    I power my oil boiler and circulators in my house with forced hot water heating with 2 deep cycle batteries and an inverter during outages.  This allows continuous heat while not having to run the generator all of the time.  I run the generator a few times a day to keep fridge cool, and cook and do dishes and of course the battery charger recharges the batteries at same time.  As such I need only run generator 2-3 hrs per day.

    Ray Frechette

    ABYC Certified Marine Electrician.
  • jumper
    jumper Member Posts: 1,713
    another millivolt fan

    I'm with Binnacle. Just keep a spare thermocouple; use gravity and heat will available. Especially when you have more than one boiler.
  • Toymotorhead
    Toymotorhead Member Posts: 54
    edited January 2014
    Transfer Switches and Inverters

    Not to drag up an old thread for no reason. But in doing some research in inverters for another project I discovered a very important fact in regards to most portable inverters.

    If you are going to try and use a transfer switch with a portable inverter on your furnace, You **MUST** use a transfer switch that also switches the Neutral. (or completely disconnect the circuit from the rest of your house, but I'm not going to get into that, or the 17 other dastardly ways to make it work)

    The reason for this is in most small power inverters (anything not designed from the factory to be permanently hardwired into a panel, and pretty much anything under $500.00) have an output where hot and neutral are both 'live'. If you take a multimeter and meter from ground on the battery input to the ground on the outlet you will find that they are tied together (0 volts potential) If you then meter between the hot and the neutral you will get in the neighborhood of ~110VAC. But if you meter from hot to ground, or neutral to ground you get around 60~80VAC on both hot and neutral

    This has to do with the design of most portable inverters, it is not a flaw, its just the cheapest way to make the electronics and the circuit in the inverter work. And it really makes no difference when you are running your laptop in your car.

    If you try to hook that same inverter with transfer switch that does not switch the neutral, where somewhere in your house neutral and ground are tied together, something bad is going to happen. If you are lucky, the inverter shuts down or you blow a fuse, but more times than not, you will damage the output stage of the inverter and render it completely useless. And remember, that in this case it is a completely useless inverter, in a cold house, with a cold wife and kids, during an ice storm.

    Just a quick heads up,


    If you can't be good, at least be good at it.
  • jumper
    jumper Member Posts: 1,713
    against code & custom

    This is one reason why plug in is better than hard wired switch.
  • Toymotorhead
    Toymotorhead Member Posts: 54
    Transfer Switch

    If you look for a single circuit transfer switch, you can find ones that will switch the neutral also. There are also multiple circuit transfer switches on the market now that have neutral switching capability. The two most common ones I have seen are the "EZ Generator Switch, switched neutral" and one made by a company Called "Heezy LCC, HTS15 Auto". I do not believe that the single circuit transfer switch from Reliance Controls has a switched neutral option. The manufacturers are catching up now that many jurisdictions require new portable generators to have GFCI protection on the outputs.

    The plug and socket is an option. My furnace actually had that when I moved in, but I removed it very shortly after I moved in. It was working but it was definitely done very poorly.

    Also it completely bypassed the firematic temperature cutoff and the emergency off switch outside the basement door. If you want to wire something up like that you have to be conscious where in the circuit you put the bypass.

    If you can't be good, at least be good at it.
  • Toymotorhead
    Toymotorhead Member Posts: 54
    Sorry for beating a dead thread

    My apologies for beating a dead thread, again. But I am currently dealing with some emergency power systems at my real job so I am neck deep into some of this stuff right now.

    I just received this email from a representative from Reliance Controls that they are indeed producing a single branch circuit transfer switch that will switch the neutral. Email Below:


    Hello, thank you for the inquiry and interest in our products!

    Yes we have recently released a TF152W and TF202W that include two toggle

    switches instead of one, as the 2nd switch is used for the circuit neutral.

    These are available but they are not yet online or advertised as we just

    finalized everything last week, such as the instructions, packaging and

    labeling.  You can order one through any distributor as a special order, we

    have sold a few so far through the company but we will also be sending out all of the information to other distributors over the next few weeks.

    Best Regards,

    Reliance Controls


    I am waiting to see a full spec sheet on them. I am hoping that they are UL listed like their other products. I frequently run into the specification that  jobs I bid where all equipment has to be listed by UL or ETL or CSA or CE. But that is work related, not steam boiler at my house related.


    If you can't be good, at least be good at it.
  • Shalom
    Shalom Member Posts: 164
    edited January 2014
    Maybe that's why my inverter blew up.

    I've got a two family house with two boilers here, one for each apartment. Mine is an old Peerless G-460-SP installed around 1962 by the future Mayor of Hasbrouck Heights; the tenant's unit is a more modern Utica PEG-112-CDE installed a few years back.

    My unit is a millivolt system, requires no external power source whatsoever, and will (and has) happily run when the entire city has no electricity. The tenants' unit is powered by a 24V, 2A transformer, and without juice will sit there like a wart on a pickle and do nothing useful.

    When we lost power after Sandy, I've long had an inverter for just such an emergency (cheap Coleman 400W unit), so I hauled it out and a fresh charged 12V 8Ah gel cell to power it with. (I also have a deep-cycle AGM marine battery in my truck for when that runs out, but figured I'd start small.)

     I disconnected the transformer from its AC input, wired a plug on the input leads, plugged it into the inverter and fired everything up. The damper opened as usual, the solenoid that opens the gas valve (or maybe it was the ignitor) hummed a bit, and then the transformer let go with a bang, immediately followed by the inverter.

    I went out and picked up a replacement transformer (this one with a built-in plug) from an alarm wholesaler, and a replacement 40A fuse for the inverter; unfortunately the inverter blew the new fuse as soon as I applied 12V, without even any load attached yet. So that didn't work either. Wound up letting the tenants use my apartment and I stayed by my parents in Brooklyn. (Of course Brooklyn lost power a couple hours later. Oh well, I tried.)

    Once power was restored, I was able to power the boiler with the plug-in transformer attached to an extension cord, until PSE&G was able to come and replace it with a new hard-wired one. They tried to give me a hard time about messing with the wiring, saying that it might void my Worry Free contract, but I asked them what was I supposed to do, wait a week without any heat until they finally decide to show up?

    Still not sure what fried the transformer, nor how the fried transformer managed to kill the inverter beyond simply blowing the fuse. I've replaced the inverter (another cheap Harbor Freight unit) but might look into finding one with 24 volt output.
  • SWEI
    SWEI Member Posts: 7,356
    Not likely

    One of the more important functions of a transformer is galvanic isolation.  Within reason, it doesn't care what the voltage is to ground, just across its winding.  A differential output stage will neither know or care, and in fact this is the best way to prevent such a design from introducing ground noise.