I have a question, not garden related, about residential hvac. If anyone in the trade/industry might be able to provide insight.
I like to figure things out.
We recently had an issue with the oil furnace/hot water boiler. We woke up to 80F temps upstairs, when the thermostat is set for 73-74F. The thermostat wasn’t calling for heat.
It appears as though there are two “loops” for the hot water, one for the lower two floors (basement and main floor - with a thermostat on the main floor, none for the basement), and one for the top floor - with a thermostat on the top floor.
Out the top of the furnace, there is a vertical copper pipe which splits into two horizontal copper pipes (like an ‘F’ shape). Each one of these horizontal pipes has a “motorized control valve” inline with it.
Would this behavior be indicative of one of those valves getting stuck in the “open” position? Because after some light “troubleshooting” and thinking about how it’s behaving, this is what I think the issue is. The valve that controls the flow of hot water to the upstairs/top floor got stuck in the open position. So, for example, whenever there was a call for heat (downstairs), hot water was also getting pumped and circulated through the upstairs “loop”.
This happened about a month or two ago. And after some thought, I turned off the furnace power until the upstairs temp came down to where it should be based on thermostat set point, then I turned the furnace power back on. It went back to operating ‘normally’ again, until last night.
One spare bedroom in the upstairs, which had the door closed, was 94F when I opened up the door.
Thanks.
Edit: I have no idea why the editor is randomly italicizing parts of my text right now.
That sounds exactly what the cause is. It’s not a common problem, but it does happen. Had the same problem a couple years ago, but the root problem was a broken solder joint on the circuit board. It wasn’t sending the signal to shut the valve. Thankfully I’ve got a very good friend who owns an HVAC company, and fixed it in about 10 minutes. Most companies will just replace the board for around $650, but he’s taken the time to investigate Honeywell boards to figure out what the problem is. If your any good with electrical, you could try and cycle the valve manually with 120V with the furnace turned off of course.
Attempting to push the lever/switch on the side of the zone valve that I suspect works properly into the “manual” (open) position results in the expected behavior, though perhaps slower than optimal (old grease). Attempting to push the lever/switch on the side of the zone valve that I suspect is the seized or failing motor/zone valve into the “manual” (open) position results in nothing - ie: the lever and/or motor is probably seized. That’s my guess. But I think it could also be burnt out, due to being old, and dried grease for too long.
It’s good to know though about your control circuit board and the solder joint. I wonder if that solder joint caused a failure of the valve, or the other way around.
I found a great video on DIY repairing a stuck zone valve. The guy does exactly what I’d think to do. Though he has the entire motor/valve assembly off the pipe, and I’m not (yet) sure if that’s easily doable on an otherwise functioning system (I bet it is).
If our oil company includes this in the service, I’ll likely just have them do it.
When you say circuit board, do you mean the “control” board/component on the front of the furnace unit?
10 minutes to troubleshoot and repair?.. They know what they are doing!
Third party folks doing board level repairs is rather unusual. As you have noted, most swap a board and call it a day.
To be fair the complexity of the PCBs really goes up with high efficiency units…
My friend did strictly board replacements when he was working for an HVAC company, and started investigating the what and why they were failing. He discovered that the Honeywell boards, and pretty much just the Honeywell boards have weak solder joints, and is a quick fix. He said most other manufacturers boards end up burning something up, thus needing replacement.
Since he started his own company 15 years ago, he stocks repaired boards in all his trucks, if needed, swap boards out, and take them home and repair them. He won’t replace with a brand new board if he doesn’t have to, just reflow some solder, or swap with a repaired board. It saves the homeowner money, and gets him more work in the future when the homeowner has real issues.
I can see how that might come about. Typically the boards are mounted where they get some intermittent vibration from the fan.
Most companies do not have in-house facilities for HALT (highly accelerated life testing) testing and maybe only test new designs (most PCBs are modifications of previous work).
I’ve seen enough ‘localized weirdness’ crop up on testing re-spins to know “test everything” is always the right answer.
The component I think you’re talking about, on my unit, is a small box with a cover on it (honeywell) that’s on the side of the KERR furnace. I’ve been under the cover plenty. There’s some “hi” and “low” thermostatic “dials” that one can turn to adjust what I think is the essentially the min and max temperature that the water gets heated to.
I hope it isn’t a control board. I’m still doing some research into the zone valves. But this is cutting into various other things I need to do, haha. Always the case.
That’s the board!!!
If you’re handy with a DVOM you can check and see if the signal is coming for “open, shut” and eliminating that out of the equation. It sounds more as though you more than likely have a bad zone valve though.
Had to get a valve assembly replaced in my loop this winter. I wanna say they tried to replace just a piece of it first but it didnt take so they had to replace the whole thing, valve/motor/etc.
We need a homeowner support group here, I’m a dingus in a first house and getting eaten alive by the stress and cost of so much of this stuff. Just one of those guys whos terrible with his hands. Stripped the drain boot changing oil in my motorcycle level bad.
I know it’s supposed to make financial sense to be a homeowner but two years in I can say buying this house was one of, if not the, worst decision(s) of my life.
You know, there’ve been a few occasions where I thought “do I want to join yet another forum, for a specific question, or could I maybe ask in ‘x’ garden (or other) forum where I’m already a member”. I joined an hvac forum, and in the hour after posting my question/issue there I learned everything I needed to know on youtube, parts websites, and this forum, and confirmed the troubleshooting and “diagnosis” that I’d already made prior to joining that forum. The response I got there was absolutely useless; a non answer. It is not a diy forum, but I wasn’t asking for diy advice. Anyways…
I like to do most of my own stuff, if possible. Not just for money saving (and ‘new tool acquiring’, but I’m just curious and obsessed with learning ‘stuff’ of all sorts. Whether or not I attempt to fix this or any issue, I always like to understand what’s going on and what the issue is/was.
I know about working on cars/vehicles. Especially in cold and cold/salty climates; it can be brutal work.
That’s too bad, and sorry to hear that about your purchasing a house decision.
I’d likely need and look for a tutorial on what I’m looking for volts/amps/ohms wise. But now after having a couple covers off of the valve’s motor assembly, it is obvious that the motor is stuck/fucked. If it’s not covered by policy, and I can find just the motor part, I’ll likely try to replace myself. If it’s the whole assembly, I’ll only try it if it wouldn’t involve water coming out of the system (which might happen if it’s stuck “open”, from my little understanding so far). I’m too tall for the space in there too, so it’s back breaking. Hah.
i did a quick search and found all sorts of videos to show you how to repair the board if you know how to solder. choose your model apparently. i watched one video and it said the relay that opens the control doesn’t make good contact sometimes and melts the solder contact. pretty easy to fix from the look of it.
I’d be down, man! I take care of all the day to day operations of the big old house my partner bought, including most of the troubleshooting and planning repairs and upgrades. I do my best as a handy guy but I definitely find myself searching forums and YouTube a bunch. It seems like we’ve got lots of experienced tradespeople here, I think that could be a great topic for the Smokers Lounge. I’d say my contributions would probably be in the realm of small mechanical repair (especially bicycles and kitchen equipment/appliances including commercial) and some specific things for older houses I’ve had to learn about stuff like slate roofs and horsehair plaster.
Ok guys, opened the topic “DIY Home Repair”
The OG community is a wonderful group of people, and @Nitt asking a question, garnered some great responses to his problem, straightforward, no runaround, and hopefully gave him some advice to help diagnose his problem.
A couple asked for a topic, so I created one to hopefully help some homeowners save a little money and get answers to problems without the runaround. The OG community is great for no BS, straight answers.
Let’s help those with issues try and get an answer, or steer them in the right direction to get answers.
It was the zone valve. And it was pretty obvious, and easy to diagnose it as the problem. It was replaced under “service contract” or whatever. So far, so good on the replacement. I got to learn something new, too.