Best Of
Re: Leaking new vents?
Is the boiler piped properly and producing dry steam? Bi-metal type vents don't handle water as well as others, and often collect and retain droplets, fail to reach closing temperature causing spitting sounds when met with wet steam (or water).
You might try experimenting with a quality sylphon bellows - type vent on a troublesome radiator and see if it's quieter. You'll find that each vent manufacturer's product behaves differently on different systems; some more forgiving of varying steam characteristics.
Re: Leaking new vents?
At those pressures I wouldn't expect any hissing, and even less so at the start of a call for heat when the radiators are still getting heated by the steam. Closing off 1/3 of your radiators, though, will make your boiler even more oversized than it already likely is and that's not advisable.
Re: Grundfos Circ Pumps- Were the old ones better?
I've got several thousand 15-58s in service over the past 10ish years and have replaced exactly one, which was only due to the homeowner closing a valve instead of turning down the thermostat. The 15-58 is one of the better circs ever to hit the market, in my opinion. I replace at least a dozen Taco 007 annually and even a handful of the 15-42, but have never seen a DOA 15-58. I too would put money on an improper install/startup, or it's not a real 15-58. Those big box store knockoffs might say 15-58 on them, but they're not the same quality.
GroundUp
Re: Grundfos Circ Pumps- Were the old ones better?
Grundfos phased out their single speed residential pumps to be replaced by 3 speed pumps, the 3 speed pumps had been around for a long time, UPS15-58 is not by any means a new pump, it's almost obsolete as is, in some places they have to use the ECM pumps, could be here soon as well. I didn't know the pumps themselves were ever actually constructed in the US I thought they were always assembled here, Grundfos is based in Denmark. A DOA pump is either defective (covered under warranty) or is air locked (most likely scenario) for reference I have seen infinitely more "DOA" pumps come through that were simply air locked than actually DOA pumps. I would say in general 3 speed choices is an improvement in 90% of use cases, the internal check valves were added to stop nuisance calls from installers and DIY that don't understand when and where a check valve is needed. The check valve itself, being inside the pump is a less than ideal location, you aren't required to use the check valve and can take it out and pipe in your own.
GGross
Re: Identify this radiator heating element and baseboard convector enclosure
@ariccio, it seems like your recent discussions are varied enough to remain separate, but please try to streamline them moving forward if your questions are similar. Thanks!
Re: Lochinvar NKC150N - DHW High Temp Issue
That - what you have circled in blue - is the flow sensor.
Re: Lochinvar NKC150N - DHW High Temp Issue
The DHW is only heated when there is a call for DHW. Water temp when there is a thermostat call for space heating is irrelevant to the DHW temp. A sink will have less flow than the sink and shower together, so if you turn off the thermostats and open just a sink versus the sink and shower together, what happens? If somebody was messing with the space heating piping, it's probably airlocked which is what's causing the high limits and cold air temp. There isn't anything wrong with the boiler, if that's the case. The flow sensor is down on the exchanger at the bottom under that steel bracket, not the temp sensor you show in the first photo at the top- just FYI.
GroundUp
Re: 2 pipe with traps on rads. Where to set metering valve?
On a vapor system you still need the orifice plate or original vapor valve with a trv.
As to the original question, as @Jamie Hall said, you can run a conventional 2 pipe system like a vapor system with a vaporstat and metering valves. If you do it correctly the steam traps should never close and last more or less forever.
mattmia2
Re: From Tankless to Boiler
Do NOT go to 20% glycol. 25% and below is prime grounds for bacterial growth and it does deteriorate over time, so I'd stick with 30-35% if you're not going to use just water.
GroundUp
Re: Navien combi-boiler motorized threeway valve replacement
As per site rules, discussing pricing is not allowed.
Ironman