Radiator vent top is blowing off.....

Heating

I got service call the other day . It is a two story home with a steam system. The heating system has baseboard heater. s. The problem called in was that the length of baseboardin the living room was spiting steam and water. I got there and the vent top was blown off. I went to the boiler I replaced the pressure trol everything working fine psi on gauge is 2.5 and boiler shuts off. I replaced the air cent everything was working fine. Just got called today that the vents top blew off again. I am not sure whats going on. Pigtail is free of debris along with tappung of boiler. Water is clear..

nicholas bonham-carter

vent damage

what sort of vent is this? 2.5 psi is high but not that high so as to expand the vent beyond its yield. can you post some pictures, and verify the actual pressure. some pressuretrols, no matter how new will malfunction, and allow the pressure to rise up to 10 psi, but i think even that would not blow a vent apart, unless it is really cheap.

a vaporstat would give you more accurate control, but your main venting must be adequate to prevent short-cycling.

maybe there is some extreme water-hammer which has caused this.--nbc

Heating

Vent

It is a heat timer varivalve adjustable vent valve. I will check any main vents. Pressure was reading around 2.5. pressure trol set at .5 differential at 1. Not sure if gauge is correct though. I will try a different vent. Any suggestions?

nicholas bonham-carter

high pressure?

try a new gauge as well, and see if you can get one in the 0-5 psi range. [gaugestore.com]. this will also show you how much main venting you need. if  you put a vaporstat on, you could use a 0-15 ounce gauge.

i always use hoffman or gorton vents, so i don't know what the opinion of the heat timer is here, but do a search.--nbc

JK_3

pitch ????

I have seen installers run baseboard with out enough pitch to get the condesate out of the baseboard. The water collects in the vent end and then when it flashes to steam BANG there goes the vent.  When I must install cast iron baseboard in a steam system I use minimum 1/2" per foot of Pitch.  Not pretty but it works.