Best Of
Re: Asking for advice for combi boiler replacement and hydronic system upgrades
temperature rising quickly is usually caused by air locked boiler, air locked pump, or the boiler loop pump just isn’t spinning for some reason.
No power, locked rotor.
On some fire tube boilers I would hold the top relief valve open to blow out air that traps high.
I like purge and iso valves right in the loop where the tees are. This guarantees that you have purged the complete circuit. Assuming zone valves or actuators are all open.
hot_rod
Re: Testo 300
Did you get the right printer? I made the mistake of buying my Testo 300LL without the printer because I thought it would work with the printer from my Testo 320. I found that the 320 printer is not compatible with Testo 300. I believe the printer for the 300 connects by Bluetooth. With the Testo on I always turn the printer on and keep it around a foot away before I try to print anything. I don't remember doing anything special to connect it to the analyzer the first time I used it. Just make sure the Bluetooth is active on your Testo 300.
Re: What's this sudden change in radiator to condensate temperature relationship mean?
either bad probably main trap or the boiler is surging or priming and liquid water from the mains is heating the returns
Re: Curious about combustion analysis?
Yes, ideally a service tech does a test before and after service and prints the after service analysis showing that numbers are in spec for that unit. Sometimes there needs to be a tweak, some mod/cons adjust combustion themselves but the test must still be done! It's not rocket science, and if it is then you did something wrong!
Re: Rinnai RU199i Cycles On/Off then code 12
Hi all, just wanted to share my experience here. I've had a non-condensing Rinnai tankless for a few months now, and every time I used hot water in the washer or filled up my jacuzzi (large water demand for both), the unit would violently vibrate and shake my whole house. Sounded like someone was using a jackhammer downstairs. After monitoring the unit while drawing hot water, I noticed it would vibrate for a while and then the flame would go out slightly after. It would try a few more times to relight, but then it displayed error code 12- no flame.
After doing some digging online, I assumed it would be a vent issue since my gas line was sized properly and there was no issues with leakage or anything else. And sure enough, thinking about it, my big 90-gallon city garbage cans sit on the side of my house, next to the vent. I didn't think the cans would be close enough to the vent to cause an issue, but I decided to move the cans out of the way and try again. And sure enough, I turned on the jacuzzi, and there was no vibration whatsoever- the unit worked as expected.
I will update if anything changes, but I think the cans being so close to the vent was causing some of that exhaust gas to come back in the intake port for combustion, causing an issue with the air/fuel mixture, which caused the unit to shut off the flame as a safety precaution, which then gave me the error code 12. Remember that this is a non-condensing unit, meaning the vent is a pipe-in-a-pipe design, which I don't love for a few reasons but that is another story.
One of my friends has been a plumber his whole life, and he told me that the garbage cans absolutely could cause this issue. He even told me that this could possibly happen if it was very windy or even foggy outside, since the exhaust sometimes isn't able to be pushed out far enough in these conditions.
Additionally, the unit was previously set to 130 but I turned it down to 120 as well. As someone stated above, this could possibly cause issues with the flow rate or even short cycling the burner,
Just wanted to post my two cents here in case anyone else was experiencing this issue. Checking the vent would be my first go-to. Best of luck to all.
Re: HOT WATER BASEBOARDS, Stumped
Seems to be a typical flow-control valve issue. If not in those circulators you will need to install some.
Intplm.
Re: HOT WATER BASEBOARDS, Stumped
If the date codes on the 007-F5 are after 2003, then the discharge flange should accept an IFC. The part# for the IFC would be 0010-025RP. No need to purchase a complete pump with the IFC.
Hope this helps.
If you have any questions, please give Taco Technical Services a call during normal business hours Mon-Fri 8am-5pm EST 401-942-8000 and just ask for Technical Services.
Re: F&T Trap sizing on steam main
Probably not undersize — or at worst, one size too small. As @delcrossv says, you are only passing condensate, and people wildly overestimate the volume of condensate in a steam system. For example. Suppose that that steam main is handling 200,000 BTUh, and all of the condensate resulting needs to go through that one trap (which is very unlikely — most of it is likely dripped elsewhere). Even if all of it goes through that trap, that's only half a gallon per minute.
Re: Questions about wiring Nest for two-wire boiler system
@mfvreeland, we've merged your comments from the older thread into your new discussion here.
@EdTheHeaterMan, thanks for the heads up!
Re: Questions about wiring Nest for two-wire boiler system
@In_New_England and @EdTheHeaterMan , your explanations make this even clearer. Thank you very much for taking the time to explain it with visual aids. This is quite a helpful community!

