Worth upgrading 13 year old boiler to mod/con with heat pump?

[JHZR2]

My in laws 11 year old boiler a Buderus gas condensing has had three replacements of that sensor and once on control unit. Finally Bosch new owner of Buderus stopped making controller part and they have no heat situation but hot water so they finding a tech who can remove this optional part.

It saves for sure in energy however the tech calls and parts involved savings gets eaten fast with high efficiency boilers.

TBH that doesn’t even make sense to me.

The outdoor reset is a simple thermistor. And if it is disconnected, the logic resets to the default temp. It works by keeping the working fluid temperature much lower when ambient is higher. In our climate in NJ, the boiler resets to default temperature (set by what kind of radiation you have, in our case cast iron radiators) at 17F.

So loss of the non-critical outdoor reset shouldn’t result in a no-heat. You sure there isn’t a bigger issue?

Knocking on wood our peerless purefire and partner indirect hot water have been excellent.

 

[mattd]

Cleaned up all the flux residue from the pipes and sanded them down/cleaned with isopropyl alcohol. Just have have to get some fittings to fabricate a drop for the pressure relief valve, pick up some pipe insulation and if I feel ambitious add one more shut off before the water heater Inlet (ran out of ball valves I had and was under time pressure to get it working). Also noticed a couple other connections in different spots of the house that were leaking and I cut out and put in some new pipe.

 

[Thermo1223]

That tee fitting looks like it was the wrong size and the previous plumber said "f it" and just filled the fitting with solder. Good call there.

 

[mattd]

That tee fitting looks like it was the wrong size and the previous plumber said "f it" and just filled the fitting with solder. Good call there.

The icing on the cake is that the T didn’t even feed anything. It was attached to a pipe about 8” long with a cap. Both of them actually.

 

[mattd]

@Snagglefoot Thought I would update this. Temps were in the low 20s last night and this mitsu heat pump does a great job at keeping the bedrooms warm with minimal effort, however my large room with 11 foot ceilings with cathedral ceilings, while is comfortable, is slightly on the cool side (62 first thing this am). This room has an 18K btu unit that was perfectly sized if not slightly over for cooling but may be very slightly under sized for heating (I have this unit and others set on auto fan speed as well as the I-See sensor and occupancy detection features enabled for maximum energy savings and it never really kicks above medium and it doesn’t stay at that speed very long and kicks down to low/quiet when it hit’s temperature). I could up temps to make it more comfortable but that would result in more energy consumption. Over night I consumed a little over 20 kWH for a 10-13 hr period and have been averaging 2 kWh per hour to run the house, and I suspect a majority of it is the heat pump (we have electric stove, oven, and dryer). I really need to invest in a circuit monitor (sense) to track exactly how much but I estimate about 30-35 kWh to keep the house at temp for 24 hours for heat. At this rate I’d be on pace for about 1200 kWH for the month, or about 350$ worth of electricity. While this heat pump is quite efficient in my opinion to run a 4 zone 3 ton mini split, it translates to 8-10$ per day to run the heat at just below freezing. I turned the boiler on this morning and noticed a big difference how fast that large room heats up (huge amount of baseboard). So for now I’ll be running the boiler and see exactly how much it uses and make a decision which source to use over the winter. I have full confidence this heat pump will put out HOT vent temps down close to 0. The outlet temps are over 125 degrees at 25 ambient.

For reference my winter electric rate is $0.29 per kWH and natural gas is $1.81 per therm. If I didn’t have natural gas and relied on propane or oil, this heat pump would be a no-brainer to use over those two alternate fuels.

 

[Hillbilly Deluxe]

If you currently have a ducted system that distributes air, hot or cold or both, through your house, I would definitely look at upgrading to a new, inverter-driven heat pump system from a major manufacturer.

These are easier to operate on solar, they have infinite part-load control, they are much more efficient than anything anyone has ever had/known and will reduce your usage.

They are not cheap, but your power and fossil-fuel bills are going to continue to skyrocket the next 10-20 years.

 

[mattd]

If you currently have a ducted system that distributes air, hot or cold or both, through your house, I would definitely look at upgrading to a new, inverter-driven heat pump system from a major manufacturer.

These are easier to operate on solar, they have infinite part-load control, they are much more efficient than anything anyone has ever had/known and will reduce your usage.

They are not cheap, but your power and fossil-fuel bills are going to continue to skyrocket the next 10-20 years.

I have no ducts. This is ductless unit. I am extremely pleased with its performance. Even power consumption. But my electricity price is extremely high which is the only downfall. This is the latest model Mitsubishi hyper heat inverter communicating system with hermetic style compressor. 4 zone system with a branch box.

I do have solar, but it’s winter production does not make a big enough dent in power usage. I had no electric bill from March to December even with leaving the system on 24/7 for cooling.

Another option is to just use the heat pump and then carry the bills into the spring where solar production will pay for the heat I used over the winter, but I’m not there yet. I want to see exactly how much my boiler is going to consume first