Click here to Find a Contractor in your area.
Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.

Winterizing (draining) my Weil McLane FHW boiler Advice needed

Sailah
Sailah Member Posts: 826
I have a separate guest house over a barn that is not being used this winter. It runs on oil. It worked great for guests over Thanksgiving but I would prefer to drain everything including domestic water and blow out the lines. My cheap Yankee heritage I guess

I did some boiler maintenance last week including rebuilding the combustion chamber, new nozzle, new filter, new pump filter. I had already attempted to drain the system once then rebuilt the combustion chamber so filled it, fired it for 15 minutes per instructions. But despite being handy and good with tools, I'm just not familiar with how to properly do this so I come to you for advice.

The system has 2 zones, it's a small apartment. Could I ask for the proper procedure on how to do this? I have 2 large air compressors (80 gal and 40 gal) and built the air to garden hose hookup. My previous attempt, I hooked up the air to the boiler drain spigot and ran 10ish PSI, shut off the gate valve for each zone and then drained using a garden hose hooked to each spigot to the right of the zone valves. That certainly seemed to get the water out but I'm nervous that I'm missing some spot or valve and I'll end up with cracked pipes.

I have a good handle I think on how to do the domestic water from searches but happy to hear your thoughts on that as well.

Thanks!

photo 20151219_143841_zps0ficgngq.jpg

photo 20151219_143849_zpsx9wt3hti.jpg

Cleaned all the soot out

photo 20151219_110456_zpsegui2jwl.jpg

Boiler shot

photo 20151224_101545_zpsooezecha.jpg

Piping and valves

photo 20151224_101602_zpsoxx2ib2j.jpg

The cold water comes through the BPV then to PRV right below the white hose. I have the ball valve to the hot water heater closed. The garden hose spigots I have available are: hot water heater, end of cold water line (red handle), Just to left of PRV, Boiler drain, And the 2 drains to the right of the zone valves.

photo 20151224_101617_zpsgxwtt0vy.jpg

photo 20151224_101639_zpsk2e7puld.jpg

photo 20151224_102706_zpshrzuiw5h.jpg

Also how would I go about bleeding the system if I want to start it back up in say March for a visitor? Is this even a good way to do it or should I go antifreeze route? I live in MA, def gets cold, although not today it's t shirt and shorts weather!

Thanks again

Peter
Peter Owens
SteamIQ

Comments

  • kcopp
    kcopp Member Posts: 3,815
    edited December 2015
    Keep the hose where you have it.
    Blow out the water through the boiler drain just below/ before each zone valve. keep the zv closed when doing this.
    Move the hose to the next zone for the other loop.
    I would go closer to 30 psi to get as much water out as possible. I would do each loop through the boiler 2/3 times. Leave all the drains in the open position.
    You will prob have to hook up the fill valve again to stop the air from blowing out.
    Pretty simple actually... follow the path of air/ water.
  • Sailah
    Sailah Member Posts: 826
    kcopp said:

    Keep the hose where you have it.
    Blow out the water through the boiler drain just below/ before each zone valve. keep the zv closed when doing this.
    Move the hose to the next zone for the other loop.
    I would go closer to 30 psi to get as much water out as possible. I would do each loop through the boiler 2/3 times. Leave all the drains in the open position.
    You will prob have to hook up the fill valve again to stop the air from blowing out.
    Pretty simple actually... follow the path of air/ water.

    So in your advice I'm hooking up my air line to the boiler drain? I did that the first time and it worked well I believe. But I had to fill the entire water system again so I drained yesterday but this time using the water heater drain as a way to pressurize the entire system. I was careful to not raise the pressure in the boiler above 15-20 by opening the PRV. Hooking up to the water heater seemed to work well and effectively doubled my air compressor tank size.

    When you say I'll probably have to hook the fill valve again what do you mean?

    Thanks! I'm going to go out today and blow it again. Every time I switch hoses I get more water from each zone. I recently did my sprinkler system with my big air compressor and I finally stopped after there was just a tiny misting. But I was also running 70psi.

    I know it seems simple just don't want to regret not doing it the right way and have a problem.

    The upper zone appears to have a split return with a balancing valve on each return. Difficult to see but it also appears that the valves are not being utilized.

    I would consider each of those returns as a separate zone and close the balancing valves sequentially to force the water from each leg individually.

    Might not be an issue if there are no loops above the boiler room that can trap water.

    Thanks I had not considered that but you are correct there are valves on each of those returns wasn't sure what they were for. I'll shut each off and blow through them.

    Headed to Florida tomorrow and want to finish this up before I leave.

    How's your venting project going?
    Peter Owens
    SteamIQ