Pressure relief valve bad?
I'm a first-time homeowner, so please forgive my ignorance!
We have a Valiant oil boiler for our heat, which, being late July in the Philadelphia area, hasn't been running since around April. The other day, we noticed some dampness on the concrete floor around the boiler and where the sewer line exits the house. The water smelled a bit strong, like ammonia or cat pee (we have two cats and we just moved their litter to the basement), so originally I thought we had a leak or the cats decided they didn't like litter anymore.
I think I ruled out the leak in the sewer line because it hasn't rained in about two weeks and when it did rain in June (for about 15 days straight) there wasn't a problem. Coupled with the fact that the water was negligible and my wife did about six loads of laundry and ran the dishwasher twice over two days, I think the pressure relief valve might be bad on the boiler. I didn't notice any dripping and didn't think it could be the boiler until last night, but we stuck a bucket under it and it probably dripped about one to two pints between 11 p.m. and 6 a.m. I checked the boiler pressure, and it was sitting around 5 psi. The boiler is probably about 10 years old, and we had to replace both the aquastat and circulator pump this winter. I'm guessing it's not a stretch that the valve could be bad.
Does that make any sense? I'm getting ready to call the boiler guys to come round, but I'm wondering if I shouldn't get to excited about it being resolved lest I have to prepare for the shock of a new sewer line.
Thanks for any and all advice!