Prepping for the unthinkable: -13'F and no heat!

[jpass]

Inherited a GV90+ "WeilMcClain" gas fired boiler with a house I bought a couple months ago. The thing is fairly new, but I'm very unhappy with it- extremely complicated, manual reads like a surgeons guide.
I've also been told that replacement parts are incredibly.... sometimes almost mind bogglingly expensive, and that from an HVAC guy.
Well we started the thing up (paid someone $100 to come out and flip the switch, but check all the gauges and levers and tell me its ok). It ran two weeks, and now it fires up repeatedly, about 10 times an hour, runs awhile then shuts off..... but won't heat the water- all the radiators are ice cold.
I'd like to throw the thing out the window.

Perhaps I'm overreacting, but -13'F (and -11'F the next night) is the coldest weather we've had here in at least a decade. Just those two days, by EOW nights going to be above freezing and high 50 by this weekend.
But how to get through the Arctic blast without busted pipes and damage, if I can't get the thing started. There are of course, water filled radiators and water pipes all thru the house.

Its a big old two story house with high ceilings. I've got 4 oil filled radiators, figure two in the basement, one in 1st level bathroom and 1 in upstairs bath. Still, -13 below zero and a high the next day still below zero, so a stretch of about two and a half days of well subzero temps.

Should I drain the boiler?
What about shutting off the water at the main in the basement, and opening all the faucets? Or would that let cold air into the pipes. Looking for some cold prep recommendations. All I hear is how I'll have to declare bankruptcy if this white elephant boiler gets frost damaged and it has to be replaced. :/

 

[Terry]

How about picking up some electric space heaters right away to prevent the home from going below freezing?
Draining the pipes is not a bad idea for the water supplies to sinks and other plumbing.
If you drain down the boiler, that's a lot harder to bring back up. I would get some back up heat going.

It's not cold air that splits a pipe, it's water in the line that freezes.

 

[Sponsor]

 

[jpass]

I've got the oil filled electric heaters running now, two in the basement, one in the bathroom 1st level, one in the 2nd level bath.
I'm just concerned as -13'F is pretty damn cold. Will that be enough, especially with all the radiators and pipes full of water?
I wondered if shutting the water off at the main, and opening all the faucet taps in the house would make the pipes less likely to freeze (no pressure) or more (lets cold air go into the pipes).
Also I would think draining the boiler shouldn't be too hard. I mean surely you just drain the water out, and then refill it later.
This is of course, my backup plan if we can't get the thing running, but not much time to get information

 

[Plumber Man]

Shutting the water off at the main and opening all the faucets will help keep your pipes from freezing.

There's a little more to draining the water from your boiler system then just refilling it, you would need to go around to each radiator after it is refilled and bleed the air out which sometimes can be a pain.

 

[Jadnashua]

A little bit more about what your boiler is doing might point to an easy fix.

If it's trying to light off 10x per hour, it sounds like it's not actually detecting a flame. Did you actually check to verify that the gas is turned on?

A typical cycle on a gas appliance will vary some depending on the way it lights the flame. There are generally two ways: a sparker or a glow plug.

If a sparker, first thing is turn on the gas, spark, detect the flame, and run. If that doesn't happen, it often will wait to let any gas purge out of the system, then try again. If it can't light or detect the flame, after a few trials, it will shut down (on most of them, anyway). More modern ones may have a fan induced burner/exhaust system. That requires the fan to actually turn on and be sensed, in the sequence. There are often various interlocks. It could have a low-water cutoff, and all it needs is a little water added.

A glow plug/hot surface ignitor, will turn that on for a bit until it literally glows red-hot, then turn on the gas and try to detect the flame.

If the burner turns on but the circulator(s) don't run, the water in the boiler will get super hot and the overheat protection will turn on.

All of these things generally can be observed. Checking the sequence should help to isolate where the problem is.

 

[Dana]

It might still be detecting the flame but an the circulators might not be running or the aquastat controls might have gone off. There are probably a half dozen potential causes for that type of system. There is not enough information (yet) to debug it by web forum, but it might not be a boiler-specific problem at all.

At 70F indoors -13F outdoors the heat load of a typical 2500' insulated reasonably tight 2x4 framed house is about 50-60,000 BTU/hr or 15,000- 17,500 watts. At a bone-chilling but not yet freezing 35F indoors it's betwen 30-35,000 BTU/hr or 9-10,000 watts. Five 1800 watt oil filled space heater radiators strategically placed would avoid the total plumbing freeze-up. Any plumbing that runs outside the insulation will almost certainly freeze if still, but any amount of circulation will save it if the rest of the water in the house is above 35F.

If the basement is reasonably air tight it will be the warmest place in the house, heated up by the warmer subsoil under the slab, but unless the foundation is insulated (highly recommended) it will still need some supplemental heat.

 

[Jadnashua]

If a circulator is not running, depending on where it is, the boiler might be reaching the high limit and shutting itself down.

Definitely need more information to try to figure out what's up with the system.