Fun just seems to happen a lot when you're living off grid.
Folks might remember a couple of years back
when I was wrestling with my radiant heat system. The boiler kept triggering an "LWCO" (Low Water Cut Off) condition. When I began to investigate, I discovered massive air bubbles in several of the lines, and ended up calling a specialist I dubbed Radiant Mark to come fixelate it. He opined that the original installers hadn't completely flushed out all of the zones, and so over time the smaller air bubbles accumulated until they were big air bubbles and *boom* -- the system shut down for self protection.
So a couple of weeks ago I was striding past Ye Olde Utility Room when I happened to glance in and see the boiler displaying the LWCO error code again. "What the heck?", thought I. Remembering the air last time I immediately stripped off all of the insulation I'd put on the tubing to help with heat retention. Hmmm....no air? That was unexpected....
I recycled the boiler and it fire up, so I thought "that was weird" and kept on. Things were good for two days...and then there was that LWCO again.
So basically things continued in this fashion for the next couple of weeks. I noticed a couple of things that didn't quite seem right -- the pressure gauge on the front of the boiler seemed to "stick" a lot, and sometimes just recyling the boiler would "fix" things and sometimes it wouldn't. Researching online I quickly came to the conclusion that one of three things was happening -- either the gauge was bad, the sensor was bad, or the system really was low on pressure.
After Radiant Mark's visit last time around I was left with about 3 gallons of glycol, and I was pretty sure I could get the system back up to pressure -- but I wasn't 100% sure. Plus if the gauge or sensor really were bad that wouldn't help anyway....
I called ABC Plumbing again to send a guy up. Turned out Radiant Mark was gone but their new guy was Radiant Paul. I met him at the mouth of the canyon this morning (no way his 2WD van was going to get up the canyon road) and we tackled the system.
First he showed me how to check and re-pressurize the expansion tank. It was nearly charged to what it needed to be (16psi would be right for a house this size) but we got it up to spec pretty quickly. Along the way he checked what little glycol dribbled out and pronounced it seemed fine (no off odor, no odd color), indicating it had not gone bad.
So then we hooked up my bucket, plugged the fill valve into the input port just above the expansion tank and added some fluid! It quickly ran the system (which since things were turned off was basically just the loop around and through the hot water tank at this point) back up to around 15psi, so we then let the boiler run for a bit first. There was some very slight drop (not much), after which we opened up all the zones to let the system pressurize.
That did drop the pressure, though it took a bit. We ended up putting a bit more glycol into the ssytem twice more, and while we were waiting for loops to come back up to temp he walked around to double check all of the manifolds to make sure no zones were shut off and such. They weren't (thanks to Radiant Mark's work before), the loops were clearly coming back up to temp and the pressure was holding good at ~24psi (I asked for it to be slightly higher for the third floor computer room) and we called it good!
Radiant Paul did excellent work and I learned a lot from him. He's recommending that I install a glycol makeup system, which is basically a tank with a pump and a sensor that triggers should the pressure drop and puts some more into the system. It's seems like a good idea even if they're a bit pricey
--it seems a worthy investment to prevent this kind of thing from happening again. Right now it would seem that I've got a small
leak somewhere or maybe the boiler is driving off some amount such that I end up about 2 gallons short (and below the PSI cutoff) every couple of years.
But we'll see. Right now I'm pleased the system is back up to its awesome self, and looking forward now to finally
getting my backup generator replaced
(it might happen tomorrow!).
Steven in Colorado
My Construction Website
Login to Reply