Circulating Pump

PaulLandon2323

Hello all. I have an electrician by trade so please forgive my ignorance.

I need to change the circulating pump that is feeding a hot water baseboard look for an addition that I have. However it seems there are no isolation shut off‘s for this pump. I’m assume that means I need to drain the system. I’m not 100% sure on how to do that based upon the type of system I have. Do I need to drain the entire boiler? Or is there any way based upon the picture here that I can just drain the loop for my hot water baseboard zone?
Any and all advice is welcome.

Thank you

GroundUp

Close any valves you can find to isolate that part of the system from the rest, open the boiler drain below the faulty pump to drain the riser. what comes out is what comes out. After refilling though, you're likely to have to purge the system of air

Zman

From what can be seen in this picture, it looks like a full draindown. You are going to want to have a refill/purge plan before you tackle this, especially in the winter.
Can you post a picture from farther back?

PaulLandon2323

I’ll take a picture and post. Thanks for the responses. 

I’m thinking I shouldn’t do this in the winter... as a novice. I can wait until the spring. 

What kind of plan should I be thinking about?

EdTheHeaterMan

Is that a steam boiler with a water loop added for another zone?

The larger pipe with an od return configuration and no other circulatory on the return looks like a Hartford Loop made of copper.

A picture of the boiler from farther away is definitely going to make it easier to help you.

The drain valves on either side of the circulator pump is another clue.

PaulLandon2323

PaulLandon2323

Yes it’s a steam boiler but a hot water baseboard line was run. I wanna change the circulator pump but there’s no isolation valves and afraid I need to drain the whole system. 

bburd

Since that is a steam boiler, there is water only in the boiler, any wet steam condensate returns and your hot water  heating loop. There should be no water in the steam carrying pipes or steam radiators.

That is much easier to deal with than if the system were all hot water. 

PaulLandon2323

Thanks bburd. Good to know. So I just turn the boiler off and let it cool down and then drain the boiler and the hot water heating loop? 

bburd

I just tried to delete my comment above after I noticed that your hot water loop piping is above the boiler’s waterline. That situation is more complicated. Others can probably advise you.

PaulLandon2323

🥺🥺🥺

Jamie Hall

You are fortunate. It looks as though that pump is pumping away from the boiler. That being so, if the hot water loop isn't too far above the boiler water line, it's easy.

You'll have to drain the boiler down below the pump to replace it. That will also drain the hot water loop. However, the pump should have enough power so that when you refill the boiler having gotten everything buttoned up, the pump should be able to refill the loop on its own, and you should be back in business. It will lower the water in the boiler a bit when you first fill the loop, but you can add some to fix that.

PaulLandon2323

Thanks Jamie!

Zman

The steam guys on here will have opinions. Some circs fair better than others in a that high temp, low head environment. Stainless steel?
I agree that the swap will be pretty simple on a steamer compared to hot water.

JUGHNE

There are 2 recent previous concerning using 3 piece bronze pumps for steam boiler water use.
Someone (not me) could give you the direct links to each, one was Indirect water heater and another was your exact heating situation.

PaulLandon2323

So just to be clear the pump is on the hot water baseboard loop. 

I turn the boiler off and just drain the water lower than the pump level,
swap out the pump
and then after I re hook up I fill the boiler again and fill the line by turning the circulator pump on and put a hose on the return side and take all the air out of the lines 

sound about right?

Jamie Hall

Sounds about right, but... if the return is into the boiler, you don't even need to have a hose. The air will go into the boiler where it will have lots of company...