Need to bleed after refilling boiler?

hockeyman70s

Hi there, will be swapping a bearing assembly on a circulator pump. Will be closing off the valves and draining the pressure out of the boiler to do so. Do i just refill the boiler with water afterward by turning on the feed water or is there a bleeding procedure to do? Thanks!

EBEBRATT-Ed

When you drain the system it will become full of air if no air can get in the water won't drain. (think holding your finger on a straw full of water)

When you refill it you have to get the air out.

Some systems have automatic air vents some have manual air vents

EdTheHeaterMan

hockeyman70s said:

Hi there, will be swapping a bearing assembly on a circulator pump. Will be closing off the valves and draining the pressure out of the boiler to do so. Do i just refill the boiler with water afterward by turning on the feed water or is there a bleeding procedure to do? Thanks!

How easy is it to isolate the circulator from the rest of the system? If the valves you are closing isolate the circulator, then you may not need to drain the entire system. (probably not the case.) If the valve you ate closing is the one on the fill valve and then you open a boiler drain to reduce the pressure, then you are going to let air into the system in order to access the circulator. Once the circulator bearing assembly is disconnected, lots of air will be introduced into the system and gallons of water will pour out all over the floor.

It all depends on where the valves are!

Yours truly,
Mr.ED

hockeyman70s

@EdTheHeaterMan thanks! I have attached a picture. The blue arrow is the bearing assembly being replaced. The red arrow I’m guessing is the drain for the boiler. The green arrow is a pipe coming out of the boiler that doesn’t have a valve on it… guessing that will drain the boiler when I pull the bearing assembly unless I drain it before hand. 

EdTheHeaterMan

That looks like a Taco 110 with an aftermarket motor. There is one trick you can try before you change out the bearing assembly. The coupling is a Spring with set screw to hold each end of the coupling on the respective shaft of the pump and motor.

Loosen one of the set screws and see if you can stretch the spring slightly. This will put some tension on the pump seal. it may or may not work.

EDIT: To make my idea more clear. If the coupling is not rusted on the pump shaft
and will slide easily... you can loosen the set screw and slide the coupling closer to the pump housing as I am illustrating here.



This will add a little tension to the seal and it may stop leaking.

By the looks of your equipment, this only has a 25% chance of working. But I would try it before draining the entire system.

Yours Truly
Mr. Ed

EdTheHeaterMan

Another item to consider is the fact that your control system is set up to maintain boiler temperature all year in order to offer Domestic Hot Water (DHW) priority. The additional circulator zone was added after the original boiler installation. This means... if you are still using the oil boiler for DHW you may experience times when you are in the middle of a shower and all of a sudden the shower turns cold.

Another problem is (if someone tried to solve the problem by adding a seperate water heater), if you are no longer using the oil boiler for DHW, the control logic of the oil boiler is still maintaining a minimum temperature for hot water that you are not using, therefore wasting precious fuel.

I realise that not everyone has 10 thousand dollars or so in their bank account so they can change out their boiler on a whim, but, that stuff is old and you should have the combustion efficiency tested. If it is below 75%, consider replacing it with something new. You will save 10 to 15% of your fuel bill on the efficiency of the new boiler. you will save an additional 10 to 15% on the thermal efficiency of a newer boiler that has a more efficient design. And still another 8 to 12% on a system that does not maintain temperature for DHW. I have had customers that have cut their fuel bill in half by replacing 1950s equipment with modern, more efficient systems.

NOTE: I have also had customers that have 1950's equipment that don't burn that much oil because the original installer knew how to properly size, and install the equipment back then. Just putting it out there... if you think you are using too much fuel, (Over 1000 gallons/Yr.) then you might think about new equipment. If you are comfortable with your fuel usage, then keep what you got in good operating condition with proper maintenance.

Respectfully submitted,
Mr. Ed

PS. If this control is what i think it is, it should have a cover on it, to protect it from dust an other basement gremlins from destroying it AND to protect you from electric shock and possabel fire damage to your home.

HVACNUT

Have you thought about upgrading the entire system?