Welcome! Here are the website rules, as well as some tips for using this forum.
Forced water baseboard system can't heat rooms to temp
I have a two story house (3 apartments - 9 baseboard heaters) that uses baseboard heating (boiler in basement). Ever since the water boiler was installed a few years ago the heating has never been great. All three apartments have put their thermostats on the maximum 90 degrees. But the rooms will not heat past the low 70s on a 50 degree day, and low 60s on a blistering cold day. Every baseboard heater is getting heat, just not very much.
The water boiler is a Weil Mclain CGa 4 SPDN. The water boiler temperature never gets very hot. 140 degrees and 25 psi or so under load. I can see the low is set at 140 and high at 200.
I've bled all the air from the three zones, but there wasn't much in there. Though after the first zone a bit of black gunk started coming out. That made me think the rubber bladder in the extrol might have failed, but it is indeed half hollow, half filled based on tapping, and half warm, half cool, based on touching.
I was thinking that they might have undersized the boiler, but the low water temperature makes me question if something else is wrong. In order to test how possibly warm it could get, I left all three zone valves to open. Shouldn't the boiler fire endlessly when this is done? Instead, I find the boiler turn itself off after 15 minutes or so(cold star, after bleeding) though the taco is still circulating the water.
I already called in a "professional" who was well reviewed on yelp. He said the flue damper wasn't always opening and switched it out to a new one. He just ended up scamming work. There was absolutely no difference in heating temperatures from before and after, and he charged $ to tune the system, clean the boiler, and install a new part. The person who was "watching" him was an oblivious woman who said he never did anything with water, and was out in less than 1 1/2 hours. He didn't even bother bleeding the system, in all his tuneup work. But he did say the system was working fine, and since all the baseboards are getting some heat it's something else. I don't trust that assessment at all.
Any ideas what the possible problem could be?