Replacing & Cleaning Boiler Valves

Jakek

I recently bought a house with a boiler in good condition. The boiler turns 30 this year (They left the original receipt) but the previous owners have been religious about keeping the LWCO and boiler clean. I hope to follow in their footsteps.

The drain valve on the boiler needs to be replaced. (Pix #1) The handle has corroded off and while it can still be operated with a screwdriver, it's a pain. Do people have recommendations for replacing it? I know it will entail draining the boiler. How big/risky of a job is this?

On the other side, the valve on the condensate return inlet appears to be clogged. (Pix #2) I can easily turn the knob but not a drop comes out. The lower valve is fine but since it's connected to the water supply (via another valve) opening it only outputs crystal clear water.

BTW, the former owners left they copy of The Art of Stream which has been an excellent read, as has this forum. I was surprised the former owners had the Pressurtrol at ~3psi. I've since replaced it with a vaporstat. I could probably heat fine with even lower pressure but that vaporstat has a nasty habit of not turning back on if the pressure doesn't get to at least 7oz. (Monitoring on a 0-5psi gauge. Markings on the vaporstat are useless.) I figure 4oz or lower would be fine for this house!



Note: Clogged valve partially obscured by the water heater gas tag.

STEVEusaPA

The valve looks easy enough, looks like teflon tape. Spray spray spray with penetrating fluid. Big wrench on the bushing, smaller pipe wrench on the valve.
Little harder to see what's going on with the return. But to properly flush (and maybe replace) you're probably going to have to crack it open somewhere, at which point you can inspect and put the right combo of valves on for further maintenance/flushing.

Leonard

On most rusted nuts or pipe I've found heat works wonders if they are stuck. Heat on "nut" part to maximize it's expansion, and if have to wet rag on "bolt" part to minimize it's expansion. Want max temp difference between the 2.

I've even used freeze spray on the "bolt" ( car brake hoses)

Just watch out for anything flammable nearby, and steam from rag.

EBEBRATT-Ed

Put a wrench on the drain valve and wrench it out. The bushing will not move. If you have any hesitation wait for the heating season to end. Same with the valve on the low water cutoff

Jakek

My question that started this thread was boring and basic but here's an update nevertheless.

The two valves I was concerned about came off like butter. The one on the return side was clogged but a stab with a screw driver cleared it up quick. (Not too much muck.) On the drain side, I replaced the valve and extended it 3" with a brass nipple to put it in a better spot for the bucket.

I ended up buying a new MM67 LWCO because the one on the boiler was ~30 years old. But this was probably a waste of money since the original one was surprisingly clean on the inside.

There was no skim port and the relief valve is blocked with the condensate return pipe. I was able to remove the 3/4" -> 1/4" brushing on the pressure limit port and added a tee to provide a skim port. I had previously replaced the pressuretrol with a vaporstat but after reading about the flakiness of the new vaporstats I put the old pressuretrol back in series so there's now a backup pressure limit.

Attached is a photo of the skim port in use, complete with a home brew viewing port. It also shows the new configuration of the limits. (Feedback welcome.)

Needlessly to say, I wouldn't have come this far if I didn't spend so much time reading other's posts on the Wall. Thanks everyone!

gfrbrookline

Looks good!

You will have to adjust the settings on the vaporstat, try 12 on the main and 6 on the diff.

Jakek

Thanks, although is there a reason to go higher on the vaporstat? The markings seem meaningless. I kept adjusting it down until I got it to trip at 6oz (according to the gauge) and release at 0oz. The rads all get nice and hot. I tried to go even lower but the vaporstat wouldn't release once tripped.

ethicalpaul

That is a good way to set it imo. The gauge on those controls is very “general”