Ask Your Question

Angie's List Answers is the trusted spot to ask home improvement and health questions and get answers from service companies, health providers and consumers. For ratings and reviews on companies in your area, search Angie's List.

Top 30 Days Experts
Rank Leader Points*
1 kstreett 240
2 Guest_9020487 110
3 Guest_9190926 105
4 GoldenKid 100
5 ahowell 95
6 KnowledgeBase 95
7 skbloom 80
8 Guest_98024861 70
9 Guest_9311297 70
10 Guest_9400529 70

*Updates every 4 hours

Browse Projects By Category

Question DetailsAsked on 12/23/2016

burners will not light in steam boiler. everything checks out. can contro relay or gas valve be problem?


Do you have the same question? Follow this Question

2 Answers


Possibly, but less likely than a bunch of other possibilities.

Obviously, with all the different brands and controls and such, I cannot hope to actually diagnose your issue. Here are some common causes, in order from roughly more likely or common to more remote a possibility, though of course if quite an old unit (say over 20 years) then pretty much any cause is on the books as components age :

0) thermostat improperly set, got knocked to OFF or A/C, or batteries dies in it

1) thermocouple or thermopile has failed - easy DIY replacement job for a mechanically home-handy person

2) if high-efficiency unit (exhaust through PVC pipe) check for frosting up or water in the exhaust pipe, or water not draining out of exhaust drain tubes

3) also if high efficiency unit - if unit kicks on but then shuts the burner off in a few seconds, then likely exhaust eductor fan is not kicking on or exhaust damper is not opening, or the exhaust pressure differential sensor has tripped because of improper exhaust pressure differential

4) if relatively modern unit, check status lights - could be a rollout or firebox temperature sensor or such has cut power to the gas control valve because it detects flame or overheating where it should not be

5) if you have no power to it but restofhouse has power - all status lights are out, circulating pump not running - check power supply - likely either tripped breaker or dead transformer

6) controller (relay box) has a problem

7) secondary overtemp safety thermostat has kicked off (usually mounted on pipes just above boiler)

8) gas control valve has a problem

9) gas supply issue (unless in most cases if other gas appliances are operating normally)

Answered 3 years ago by LCD



This is Erick in Member Care. Thanks for your interest in Angie's List!

We'll be happy to help find top rated providers to fix your boiler, but it doesn't look like you have a subscription to the List yet. You can join by visiting or by giving us a call. Our call center is available 8:00 am-9:00 pm weekdays and 8:00-5:00 pm ET on Saturdays.

Thanks for your question and we look forward to assisting you!

Answered 3 years ago by Member Services

Related Questions

Terms Of Use
Privacy Policy