Best Of
Re: Water heater as buffer tank
This is the control I like to use. It has a lot of adjustability, nice readout. Other versions from HW and Johnson controls. The sensor against the metal tank jammed under the tank foam insulation is accurate enough.
hot_rod
Re: How well is my heating working at lower water temps?
As was mentioned earlier, it is difficult to dial in the fan coils with modulating input boilers. Especiall;y with the outdoor reset feature. The fact that you have a boiler that will modulate supply water temperature based on the outdoor temperature should eliminate any on off cycling of the boiler once the outdoor temperature drops below the boiler’s turndown ratio minimum input requirement. As the outdoor temperature drops the boiler should increase in temperature to the fan coil that runs constantly. Best if there is an air handler with a variable speed fan to adjust the fan speed as the outdoor temperature changes. Thus it will have a fan that never stops (just changes speed) and a boiler input that constantly adjusts the water temperature to the fan coils based on the outdoor temperature.
Since there are no controls for that particular combination of equipment currently on the market for general use, You will probably never get the efficiency you might expect from a radiant floor system or cast iron radiator system. That said, the combi has resulted in lower fuel usage from the original “on/off” boiler system from years ago. I have a feeling that you are going to keep adjusting for some time, Until you have a real issue to resolve like a daughter getting married or a parent going to the nursing home. That usually takes focus away from heating systems. Even for the engineer types.
Re: New Return Pipe Noise During Renovation
The way that main vent is spewing the pressure seems excessively high, but until you get a gauge on the boiler we'll never know. Excessive pressure can damage some vents.
Seems like with the pipe congestion behind the wall a false water line piping is your best option, explaining it to who gets to do it may be interesting, unless they know steam systems. One example;
https://www.comfort-calc.com/Steam_False_Water_Line.cfm
109A_5
Re: drain baseboard heat
Yes, thats the arrow and No, you are not an idiot. You are asking very good questions.
Intplm.
Re: Heating an Old House: Gas Heat Options
What about a heat pump for 2nd floor with possibly, probably some supplemental heat & then the radiant for main floor. The supplemental heat could even be a water coil in duct off boiler if you like. Or maybe the #s work for heat pump only but based on your climate zone, heat pump could come up short some of time. Depends where you actually are on map and how well insulated you will be.
Good luck
Re: Indirect HW off steam- shaking circulator
You will not get very much heat into the indirect, if you're only flow is through the bypass loop. And just for the record, I have piped many indirect off of steam boilers, without any bypass loop.
Re: Indirect HW off steam- shaking circulator
I see no need for a flow check. All the flow check does is add a restriction. Its purpose is to prevent gravity flow. The amount of gravity flow from the top of the boiler to the bottom of the boiler is negligible.
As far as the flow through the indirect it should be as the tank mfg recommends. However reversed flow may not change the operation of the tank that much.
I would assume they would put the hotter boiler water into the lower coil tapping as you will have colder DHW at the bottom of the tank don't know if this is true.
Re: Indirect HW off steam- shaking circulator
@WilliamME … I have been following this for a while and see that you have asked if several different things can work outside of repiping the system correctly.
My first thought after looking at your pictures is to open the FlowCheck valve to the manual open position and flip the circulator pump to pump from the bottom of the boiler to the water heater return tapping. Just turn the circulator around. That is easy with the valves there. You could do that yourself. This will be positive proof in your mind that pumping away from the lowest point in the boiler WILL solve your problem.
If you find that the water heater overheats when the circulator pump is off, then you need to install the flow valve properly. That will involve some repiping. At that point you should have it done correctly.
Re: Which Viessmann boiler to buy?
You could also just replace the current oil burner with a gas power burner. 20 years is still pretty young for a boiler. It could leak tomorrow or it could last another 30-40 years. Without some heat loss calculations you don't know if your current boiler could pick up your loads or not. If the conversion to gas is propane it likely isn't going to be cost competitive to oil. The 125 gallon tank probably can't handle the drawdown of a boiler in winter so the new propane tank would be a significant expense. The cost of replacing the boiler is going to far exceed any fuel savings once you account for the piping and trim and labor.
mattmia2
Re: Which Viessmann boiler to buy?
I would say the Vitorond or the CU3A would be good choices. Both boilers are very good. The issue I've had were the CU3A would have been a great choice for a replacement boiler was ceiling height in a"Michigan" basement. Basically a glorified crawl space. I just didn't have the headroom for the boiler. The CU3A is easy to connect to a majority of piping arraignments with little modification. The CU3A is going to give you a few added features with the controls like OAT reset.
The Vitorond casting is well built, but heavy to move . We had a customer purchase one and put a waste oil burner assembly on it for his shop. I attached a pic so you can see what the casting looks like. A plus on the Vitorond would be that you can change over the burner to gas at a later date if you decide fuel oil is no longer the route you wish to go.
The question is what fuel you would like to go with now propane vs fuel oil. Factoring in the fuel oil tank replacement vs a 1000 gallon propane tank installation is sort of a wash. I would treat this as a separate bid then compare just the boiler installs. We don't discuss actual prices here. As for the Carrier acquisition of Viessman, I have not yet seen any changes in service from our Viessman rep or supply houses. It's still my go to mod con boiler choice.
