Radiators not heating up

Question

I'm in a house that has steam heat (or it at least has a boiler and some kind of water-based heating) and the very small profile baseboard radiators along the walls. The thermostats are both set to 80 degrees Farenheit and the temperature of the house is about 58 degrees upstairs (main level) and 65 downstairs (basement). I have a space heater running near the basement thermostat.

I examined the boiler but to me it isn't obvious there's any problem. It periodically makes some noise like it's doing something, and some of the pipes coming out of it are hot enough to burn me. Two of them - which have metal devices with wires coming out - are perfectly cool and safe to touch. The gauge on the top of the boiler says 225F and ~24PSI.

A big tag on the boiler says CAC / BDP - Indianapolis, IN at the top and Series PWB-4D, model BW2AAN000105ABAA. Says "low pressure boilers" in the certification area. Attached is a circulator pump with the brand Taco, model 007-F5, HP 1/25, Amp .71, 60Hz, 115v, RPM 3250. The pump is hot to the touch but doesn't burn me. There's a tank attached to the pipes that burn me that has the brand AMTROL and Extrol on it and says it is for expansion in a hydronic system.

The smaller electrical boxes which must be zone valves are Honeywell model v8043f1036. I do not know whether they're working or not.

How can I safely "reboot" this so that the baseboard radiators will start radiating? The heat worked last winter. Is it possible there's some circuit breaker or something that has to be switched on when the seasons change? The house also has the sort of AC where there's an external fan unit and a cold air blower in a few of the rooms.

Answer 1

based on what u are asking and what is evident you are not knowledgeable about the simplest answer is to call an HVAC company to come out for a no-heat service call - and describe the situation, and maybe also ask for a boiler tune-up.

• from your description u don't have steam heat; boiler pressure (gauge) would only be a few psi at most not 24 psi
• the pressure gauge on the boiler often is broken and never reads correctly, the needle can simply be stuck, so u need to validate the system pressure some other way
• from your description u have basic hydronic baseboard heat, u can web search on that to learn more about it. It is fairly simple.
• simplest explanation in your case - any one thermostat actually calls for heat at the boiler controller, which there may or may not be zone valves; if the boiler fires then that is significant in the troubleshooting process, then is the cirulator(s) being powered and functioning, and then is the expansion tank ok, and is there no air in the system?
• start with finding the tag on the boiler and circulator and zone valves for make & model number to know what u got

Answer 2

There's a high chance you'll need a callout, but it's worth going through a few of the basics first.

Bleeding radiators (DIYable)

Radiators usually have a bleed valve at the top, to allow you to let out accumulated air. I tend to have to do all of mine about this time of year (not immediately after starting to use the heating, but a little later) and might need to do one or two again. The usual symptom is radiators that don't get as hot at the top (maybe you would have noticed that last year), but a system badly full of air can take a fair bit of bleeding, and the air can stop circulation for whole sections of the system. You'll need special tool, called a "bleed key" where I am but terminology varies.

Some systems also have a bleed valve on the pipework at another high spot.

Error codes (DIY, useful information for a pro)

The boiler may have a display (it could be as simple as flashing LEDs). Any error codes or unusual flashing will be very useful information.

Boiler Pressure (DIY)

On sealed systems, things can fail if the pressure is too low. This probably isn't your issue as the boiler must be firing and your 24psi seems reasonable (I had to sort one out recently which needs 1-2 bar, i.e. 15-30psi), but don't rule it out completely. There will be a manual valve or two, and instructions in the boiler manual.

Checking thermostats (DIY)

This isn't as easy as it might be, but get an assistant to turn it right down and right up, while you're near the zone valves. They should hear a click with many models, you may be able to hear the valve actuating, or see/feel an indicator. Generally this requires the heating to be set to on. There may be a master thermostat near the boiler or in the hallway; check that first and leave it turned up for the duration of testing.

Clearing out any filters (DIYable, probably)

My system has a magnetic filter that catches some of the iron-based crud that accumulates over time. There are various types of filter. These normally have a flushing procedure, which might need doing once a year.

Chemical flushing (DIY or pro)

I do this every other year, and for me it's DIYable, but I have a vented system that's slightly easier and needs less kit. If you're getting someone out to look over your system, getting them to flush it would be a good idea; they may be able to pressure-flush instead or as well.

A build-up of sludge tends to first show as radiators that stay cool at the bottom, so isn't always obvious; one of mine, under the kitchen cupboards, gives up completely (or rather its thermostatic fan does) as it collects the most muck.

Boiler Servicing (pro)

Boilers should be serviced, normally every year. This is a job for professionals (legally, here, because it counts as work on the gas system and that's restricted). However yours is getting pipes hot so it's working - but a service is another thing that's worth building in to a visit if you get one.

It would also be worth checking whether the same system provides your hot water (and whether that works). It's common in some places for one to do both, and that's useful information when troubleshooting or getting someone to troubleshoot.