Even though boilers are dependable, everything breaks down over time. Especially true without annual maintenance. Here are a few common boiler repair problems. If you need trusted advice call the oldest local boiler expert – PDM Plumbing, Heating, Cooling Since 1885.


Boiler no heat?

Has your boiler stopped working, and you’re not sure why? Unfortunately, this is not always an easy problem to diagnose. Two common problems are your pressure level and your thermostat. You could have a broken diaphragm or airlock, issues with your valves, or water levels. Even safety switch, aching pump, faulty ignition may be the cause. We need to test various systems, diagnose the problem and discover service options.

Thermostat not accurate?

The boiler thermostat controls the water temperature circulating through your boiler system. The thermostat also supplies hot water to your radiators.

How to troubleshoot your thermostat.

We assume you have a digital thermostat.

  1. Is thermostat turned to “on” and the proper settings?
  2. Check the power circuit. Are the thermostat and the boiler receiving power? Check your circuit breakers and make sure.
  3. Replace thermostat batteries. This alone resolves many thermostat issues.
  4. Clean it. Some thermostats open easily so you can clean the inside. Others will require that you unscrew the faceplate. Dust, and other dirt can affect performance. Brush the inside gently with a dry, clean paintbrush. (Compressed air also works, but follow all safety instructions on the can.) Turn off power to the thermostat’s circuit and remove batteries before doing this.
  5. If problems continue, replace thermostat.

What are boiler thermostatic radiator valves (TRVs)?

Installing thermostatic radiator valves (TRVs) on individual radiators allows you to have different temperatures in individual rooms.

Why does the pilot light go out on my boiler?

A common cause for a pilot light to go out is the thermocouple. The thermocouple’s job is to shut off a gas safety valve when the pilot light goes out. A faulty or blocked gas valve is another possibility. Do you have to light your pilot and leave it running so heat is always available? Or does your boiler use electronic ignition to heat water only when needed? If you cannot ignite the pilot light, you’ll need a PDM Heating technician to bring back comfort. It is safe to light a pilot light with a gas lighter. Before turning the knob from Off to the Pilot position, wait until the gas smell goes away (minutes).

Why is my boiler making loud banging, whistling or gurgling noise?

Air in the system, low water pressure or imminent part failure can cause these noises. Also a blockage or sediment at the bottom of the boiler can cause noises.

Boiler rumbling or kettling noise.

This is a major hot water boiler problem. Lime and sludge buildup can limited water flow. This causes water to overheat and boil. This can become a bigger problem quickly like the boiler may spring a leak or pressure builds up. The likely problem is hard water mineral buildup that changes the pressure levels in the tank. Kettling is a serious problem with your boiler system. If not treated, the entire boiler could break down.

Why is boiler pressure too low?

Your boiler pressure must be at the correct level for the hot water to circulate properly between the radiators. Water could be leaking, or a pressure valve may need to be replaced. Boiler low pressure can also be caused by radiators that have been bled recently.

How to fix frozen condensate pipe?

This pipe runs outside, so there is a risk of freezing. Melt it by pouring warm water over it or warm blanket, or hot water bottle. Try resetting your boiler – if the pipe remains frozen then address the issue itself. If problem appears again think of insulating the condensate pipe.

boiler radiatorWhy are my radiators cold? Radiators won’t heat up.

  1. Trapped air is a common boiler repair especially with one or a few radiators. Trapped air can also build up over the summer. When you first turn on the boiler air can cause radiators to be warm at the bottom but cold at the top. Bleed your radiators. Use your radiator key to unscrew the bleed screw a little, just until you hear a hissing sound. Once the hissing dies away and water starts coming from your radiator, be ready to close the bleed screw.
  2. Check for larger problem. If all of your radiators won’t heat up, this could be a sign of a bigger issue. Any other symptoms? Noise? Do you have hot water? Call PDM Boiler for expert advice.
  3. If trapped air isn’t the problem, or your entire radiator is cold not just the top, check your radiator valves. Make sure the radiator is on or valves are open.
  4. Does your boiler system need to be power flushed? Flushing helps remove sludge and debris. Radiators that are warm at the top, but not the bottom is a telltale sign, as sludge in the bottom of your radiators which can prevent radiators from being heated properly.

Boiler keeps turning itself off.

Could be caused by a number of safety control issues: low water pressure, thermostat, closed valve causing low water flow, air or pump not circulating water properly. PDM boiler repair experts can help.

Boiler leaking? 

Is the boiler tank leaking? Sorry, but that’s a real problem. The boiler probably is corroded. The good news is you’ll invest in the latest boiler technology to keep you comfortable. Is the boiler leak from a pressure relief valve or a pump? We can repair that leak. And sometimes a leak is only condensation!

Why choose the PDM Since 1885 Comfort Team?

  1. Live answering – whenever needed.
  2. Respectful – We’re homeowners too, so we’re certified, licensed, insured for your protections. We wear show covers, always clean our messes, and offer polite service.
  3. Resourceful – Determined, on-time heating boiler team gets you back to doing what you love.
  4. Advice you can count on: Our 135 years of experience offers options for any water or steam boiler maintenance, repair or installation. We won’t sell you something you don’t need.
  5. Upfront pricing – You’ll never pay more than you’re quoted.
  6. 100% happiness guarantee – Going beyond to make you happy and comfortable
  7. 1 year risk-free guarantee – If you are not happy we will redo for free.
  8. Environmentally friendly – We recycle, improve efficiency and use sustainable materials.

Your Comfort Is One Call Away.

Let PDM boiler repair experts take a look and tell you what needs maintenance, what needs repair and what can wait. Call PDM Heating Since 1885 for local boiler repairs in greater Bolingbrook, Homer Glen, Joliet, New Lenox, Plainfield, IL area. 815-207-4111.