Best Of
Re: F&T oddity
Tough to see the return line. You can lift condensate with a trap as long as you have enough steam pressure to overcome the rise in the return. Thats why they used a check valve to avoid backwards flow.
Seems like a lot of mud in the trap but if it has been 50 years I guess that is normal.
With the two unions you could easily remove the trap to flush and clean it.
Re: Replacing pressure reducing valve
I like the combo units also. They come with a union fitting so you don't need to cut pipes to replace the parts in the future. If you pipe it near the expansion tank and include an isolation valve on both sides of the setup, you can service the expansion tank, back flow preventer and auto feed PRV without draining the boiler or shutting off the house’s potable water supply. This Expansion Tank Fitting on one end and that ball valve on the other end will accomplish this nicely.
Re: Water to Water Geothermal heat pump replacement with lp boiler
Maybe @hot_rod will chime in but this it what I think.
Recommended pressure drop is 6.2 psi. At 6.2 psi pd the flow should be 16.5 gpm per the mfg.
you say that you have a 2.0psi PD and that the mfg says 2.9pd is minimum and that at 2.9 you flow would be 11 gpm.
At 2.0pd you flow is only 9.53 gpm (thats what I came up with) Cv of the unit is 6.74.
so at 9.53 gpm your flow is only 86% of the mfg MINIMUM
and 57% of the recommended MFG flow.
No surprise to me why the unit short cycles and has no capacity.
You need someone who can size the correct circulator for you to get the proper flow. Too many installers guess. That doesn't work for me.
Sometimes they get away with that approach but more often they fail. Heat pumps need the right flow
Re: Cost to clean a heat exchanger?
What type of heat emitters? How many?
Running the boiler at low return temperatures for extended periods in another cause of sooting. Did he look up inside with a mirror? Or remove the top?
hot_rod
Re: Cost to clean a heat exchanger?
Did the tech leave behind a printout of the combustion test? At 3 years old, that boiler should be spotless inside. At 20 years it should be spotless. If there's soot, then the tech needs to find out why, not just clean it.
HVACNUT
Re: Cost to clean a heat exchanger?
Natural gas shouldn't be sooty unless something else is wrong. I've cleaned mine myself. You'd need flueway brushes but honestly a long cleaning brush for fridge coils works fine and lasts longer. Be sure to cover the burner tubes with a piece of cardboard to keep falling crud from plugging the gas ports. It'll be easier to vacuum up too.
Re: BACKFLOW PREVENTER ON HYDRONIC BOILER, NOT SURE IF THIS IS FAILING OR NOT
If the main shutoff up stream is not sealing 100% and there is not enough flow or pressure to slide the spool over the vent, AND something is stuck in the first check, then you would see a drip coming out the vent. It's actually doing it's job protecting the system against a failed check.
Rust, sand, teflon tape, etc in a check valve can cause a check to not seal.
Generally there is a small strainer in those small dual checks, but it does not catch all the small particles.
They are fairly simple to disassemble and check/ clean, to large nuts remove all the guts.
However if it is old, 10 years or more the o-rings and seals could be deteriorated or nicked. Time to replace it, it is an inexpensive safety device that protects you homes water supply.
Do you have a backflow on your water main into the home? That protects the city water and users from getting your water back :). The BFD on the boiler protects the water inside your home. Pretty much all plbg codes require both protection, appliances and entire building main.
Many jurisdictions are now requiring an RPZ type dual check on boiler feeds, a higher hazard listed valve, since they don't know if any chemicals may be in the boiler water. Those will require a yearly inspection by a licensed backflow technicians however.
Another option is to disconnect from the water line and add a fill tank, like an Axiom.
hot_rod
Re: Thermal break for new radiant heat slab in older attached garage?
Yes you need a thermal break.
BUT
The foundation does not, or should not, support the slab. They need to be structurally decoupled from each other, or you will get serious cracking at the edge of the slab.
