I am not getting heat in two rooms served by the same supply for baseboard heat. When I attempted to bleed the system at the baseboard valve, I got am immediate air vent then a slow vent of air with a small amount of water that followed, then nothing. My system is registering @ 5 PSI at the furnace. It is a Dunkirk High Efficiency gas hot water furnace. I should note that this has been a problem this year, but in the past these two rooms were my hottest. Any advice as to how I can get it bled?

5 PSI at the furnace

Your pressure is to low. Set at 12 psi and maintain while bleeding. If you have a auto fill valve it will need to be adjusted. The higher pressure will cause more altitude in the system allowing more water to the second floor. This will also allow a good bleed.

Quote:

---

Originally Posted by hvac1000

5 PSI at the furnace

Your pressure is to low. Set at 12 psi and maintain while bleeding. If you have a auto fill valve it will need to be adjusted. The higher pressure will cause more altitude in the system allowing more water to the second floor. This will also allow a good bleed.

---

Thanks. I am a do it your-selfer. I take it that you mean for me to adjust the pressure on my auto fill valve to allow it to fill to 12 PSI. And, that I can do this by loosening the lock-nut and adjusting the pressure with a screwdriver. Is this correct?

Yes. Turn the screw down for more water pressure on most regulators. Easy does it a turn at a time or you will overshoot and then have to play the back it up game. Most regulators come factory set at 12 PSI and we do not know why yours is set differently or if yours is defective if you follow my drift so keep your eye on the ball. Also if the pressure rises a lot when the boiler comes up to temp you might have a full expansion tank or bad bladder in a bladder style tank. I do not suspect this at this point just something else for you to watch out for.

Pressure regulators do go bad and once you get it set to 12 PSI or so it should automatically maintain that pressure. If not then the regulator is probably toast.

One last item. In most 2 story houses about 12 PSI will do it but I have seen where 15 or so was necessary to keep a good solid pressure in the system and allow a complete bleeding. I never like to see a system over pressured if not necessary. To save yourself some grief the next time put a auto bleeder at the highest point in the system. Then any air in the system will be taken care of automatically.

Raised the pressure to 15 PSI and bled the system. Still no luck in restoring heat to the rooms. Any suggestions?

Did you have water coming out of bleeder, or was it still dead. Is there any chance you have a frozen pipe? Does your system contain antifreeze? Do you have zone vavles, or do you have pumps for zones? Lets know what you find, and we will try to help further.

I bled the system and actually got hot water at one end of the radiator. Cold at the other. I have only one zone for the entire house. I purchased the house and did some remodeling. As I said initially, the system was working well in the rooms and then quit. I will continue to bleed the system and hopefully will get the heat working. I called the manufacturer and they said I could go up to and a little over 18 PSI. Do you think that would help?

Thanks

No, I don't think it will help at this point. And could cause pressure relief valve to open(once water heats up to max temp). You have bled the system until you get hot water from bleeder, but still not circulating water. You never said whether there was a chance of a frozen line.

I don't think there is a chance of a frozen line. And, I don't have any way of checking that I can think of. Do you have any suggestions?

Trace the line to and from registers in question, look for any place they come near an outside wall, and see if the pipes feel freezing cold. or if there is any air leakage from outside that could penetrate the piping.

OK. Thanks. I'll do that and hope for the best.

Keep bleeding and watch the water pressure. You could increase pressure to 18 as per mfg but you now have water to the area. Make sure circulator is operating as in calling for heat by thermostat..

Raised the pressure to @18 - 19 PSI. Rooms are now getting hot water in the baseboard heat exchangers and are getting warm. Thanks to all for the advise and support.

Joe

Glad you got it going.