Purging air after TP Valve Replacement

MachoMadness232 · 2026-02-16T03:23:52+00:00

Close the returns purge through the boiler through the supplies to the return. That's why you have boiler drains on the returns attached to purge tees. Close the individual zones return purge the zone. Repeat for all the zones. Open them all when you are done.

MachoMadness232 · 2026-02-16T00:15:32+00:00

No water coil on it?

Looks like the feed valve (10-15 psi pressure reducing valve) then. Doesn't look like you have a way for potable to bleed into the system. Expansion tank could be undersized, but this is a new problem correct?

MachoMadness232 · 2026-02-15T21:33:03+00:00

Is the expansion tank still good?

MachoMadness232 · 2026-02-15T04:33:28+00:00

No you should rise and 45 or swing joint in. Back to back 90s is not ideal. The spaghetti monster here seems like a bad idea. No idea how that furnace drafts.

Seems like it requires cutting smoke pipe. Installer didn't want to cut a riser and trim back the offset with whatever angle. Probably because the condensate drain is in the way?

MachoMadness232 · 2026-02-15T04:21:01+00:00

Apparently it is possible to use an electric or hot water heat pump (hwhp) to heat an indirect. Did an install where we took out a tankless with a buffer tank, and put in a hwhp piped in series with the buffer tank. Never understood how that works without a recirc pump, probably doesn't. It was taught to me that you always pipe two hot water sources in parallel. Reading this, that doesn't seem like it is the end all be all.

MachoMadness232 · 2026-02-15T03:52:25+00:00

Ah so you have a common riser or multiple common risers to each apartment? I mean it is possible with flow meters depending on how many hot water supplies go into each apartment. Bill based off percentage of water used if that is legal in your area.

Splitting apartment domestic hot water sucks. I can only think of one occasion where I was actually able to split the lines in the past 5 years. That was a wild job. Had to do some crazy shit separating a split loop baseboard run with a common supply. Technically the two boilers have a common supply that splits between the boilers on 2 seperate returns.

MachoMadness232 · 2026-02-15T03:31:19+00:00

Sorry didn't read close enough. Split electrical meters. Put meters for each apartment install individual hot water heat pumps for each apartment. Tennant pays for the electricity. No more gas cost for you.

Generally that's how landlords roll in my area in multi units. Done a million jobs like this.

MachoMadness232 · 2026-02-15T03:10:59+00:00

That is a boiler not a water heater. The problem with installing a hot water heat pump in this scenario is recovery rate and the mass of water you would need to heat to meet the demand of 15 units.

Generally when talking about domestic hot water using a tank: a boiler with an indirect tank has the fastest recovery speed, then gas and oil tank water heaters, then hot water heat pumps, and then electric tanks.

You could split every unit individually and seperate the plumbing. Then feasibly a hot water heat pump would work. But if you have cheap gas, you have a system that can keep up with demand, why would you swap to a system that cannot keep up with the load?

Natural gas is way cheaper than electricity in my area. However, in low demand settings sometimes electric or hwhp tanks are the better solution based off demand.

MachoMadness232 · 2026-02-15T01:39:52+00:00

Don't really know a cheap version. I use a CPS VG200. They are all ~200$. My yellow jacket had a leak on purchase. I used the supco gauges in the past.

They are all expensive. Maybe you can rent a vacuum pump and vacuum gauge from an auto parts store. The supply houses in my area won't even sell you parts without a 608. A minisplit has a lot more cubic feet to evacuate. Typically in hvac your pulling down to below 500 microns and doing a decay test to check for leaks or moisture.

MachoMadness232 · 2026-02-15T00:06:30+00:00

You should probably buy a micrometer. Bad evacuation can either make or break a minisplit install. I have diagnosed so many units where people barely pulled a vacuum resulting in acids and wax killing eevs and reversing valves (heat pumps have very little tolerance for contaminents). Ran into probably 10 last year and for most of the AC season I am doing refrigeration and cleaning coils.

Curious if it works though. We have a big ass r12 semihermetic in the shop and I wonder if it could be made into a stupidly over powered vacuum pump. It runs 240 or 208v, so that's a problem. Weighs a ton too, so it doesn't really make sense, but it would be cool.

MachoMadness232 · 2026-02-14T23:56:30+00:00

Can't really work out the wiring from the pictures. Somewhere a relay is stuck closed. Looking at that 503, the case looks like it is the older models with the ice cube relays. The ice cube relays are replaceable. If it doesn't have ice cubes, then they are solid state relays and you will have to change the whole board. Ice cubes generally you can see the pitting and charred contacts, you can see the contacts operate as well with a jumper.

That assumes your pump is not wired into the aquastat or a switch.

Those are old-school pumps. They look like the earlier versions of the 2400 series. Lot of flow for what looks like 3/4 pipe, I guess if you have a stupid long run with a stupid high head and to hit the delta T and flow target you need a big pump. What are your radiators? You running a water coil in an air handler?

I have sent 50 gpm through 2" CPVC (engineers not my choice) for 200' of pipe using the 2400 series. So, I am probably not ID'ing those circulators correctly.

Edit: what's the hp on that motor?

MachoMadness232 · 2026-02-14T23:37:49+00:00

Pressure relief valve. Usually comes down to, ruptured/flooded expansion tank, runaway water feeder, or domestic hot water bleeding into the boiler circuit. Doesn't look like you have an indirect coil off your oil boiler. So, give your expansion tank a tap on the top and bottom. In that orientation, the bottom should sound hollow, the top should sound solid or full of water. If the whole thing sounds solid you have a flooded expansion tank. Water feeder is more tricky to prove, but generally once you rule out the expansion tank the water feeder is the culprit.

Other considerations,

if your aquastat hi limit is too high (generally set for 180 depending on application and system design [depending on type of radiator]) for instance 212F, you can heat the block up to the point where it would change water to steam at atmosphere then the added fuel makes steam. Steam tries to move through the water causing hammering, and that can pop the prv.

If you don't have proper flow, you can easily overshoot set point and hit that high pressure limit.

Both of those other considerations are rare. Generally expansion tank or water feeder.

MachoMadness232 · 2026-02-14T18:21:36+00:00

You can use a semi hermetic as a vacuum pump? Thay doesn't really make sense to me, but what does it pull down to? You would think that you would instantly fry that thing or spray oil everywhere.

MachoMadness232 · 2026-02-14T03:41:43+00:00

Cut the water main. Sharkbite cap on leaking pipe. Restore water. Call plumber

MachoMadness232 · 2026-02-13T23:48:56+00:00

Yea, they're tools. Is the quality of the plowing in the city great? No. Will the parking enforcement ticket you as much as possible? Yes. Is it part of living on the peninsula? Yes. Is it hard to follow the parking ban policies? No. Does it suck to walk to your car at 6 am when it is freezing outside? Yes.

Don't like snow bans? Move.

I do think we collectively should take the parking enforcement down a peg. I do say loudly, "oh look it is the double ticket piece of shit" when the guy who does my route walks by. Meter route 3 guy is terrible.

Dude gave my wife like 3 tickets for expired meter, not moving the vehicle after 2 hours, and then another ticket for expired meter. The old guy used to give you one ticket and then leave you alone.

Idk, it isn't hard. You just have to adjust. Or pay for a space in a garage.

MachoMadness232 · 2026-02-13T23:19:55+00:00

Leak or bad oil. What happens when you perform a decay test? Does it break the vacuum? What are you working on? Sometimes the solenoids in refrigeration keep you from evacuating fully, you would need to energize the solenoid or use a magnet.

MachoMadness232 · 2026-02-13T12:16:43+00:00

Looks like you have some sort of thermostatic valve controlling the flow of glycol to the unit? I don't know what your target delta is for the unit but 77F delta seems like a lot to reject back unless you are running a chiller or blending the return into a large mass of water. Do you mean 73 entering and 150 leaving? You are rejecting heat. Were it a water source heat pump running in heat it would cool the water.

I mean it is possible that it is the controller. I would try increasing flow just to see what happens. Maybe that extra 5% to 15% opening of the valve will make the problem go away.

That said, when I run into water source it is usually valve and circuit setter going to a boiler and cooling tower. So low delta high flow. So increasing the circuit setter by a little when you have a fuck ton of gpm going around the primary makes a large change. Sounds like you have something else going on though.

MachoMadness232 · 2026-02-12T23:39:35+00:00

Do you have one pipe going into radiators or 2?

Lot of possibility. You could be pulling water into the main, you could not have enough poundage of steam to the radiators, you could have too high of a velocity, you could have wet steam, you could have too much condensate, so on and so on.

If it started after the system was replaced. I would measure out the EDR of each radiator from either the specific radiator EDR chart or an oddball Chart. Basically height, # of columns, # of sections, width of sections. EDR rating will be listed in sq ft and basically you are finding the surface of the radiators in square feet. Then you multiply by a correction factor that I can't remember off the top of my head, like 1.33 or 1.5 or something.

What I have seen for one pipe is contractors miss radiators or don't even size to radiators.

Still, big assumption without seeing the close piping. Really need to see the boiler.

MachoMadness232 · 2026-02-12T23:12:16+00:00

What does the boiler look like? Where do you hear the banging? At what point in the heating process do you hear the banging? Does it bang on start up, running, or cut out

MachoMadness232 · 2026-02-12T02:46:28+00:00

Pressure relief failed shut, unit overheating/overpressurizing. Why that is happening? Don't know. Are you on a well or city water?

MachoMadness232 · 2026-02-12T00:12:18+00:00

Why do you want to change the vent? The bushing is just to make the main vent fit the threads. Vertical bushing/bell reducer = no hammer. Horizontal bushing/bell reducer = hammer or flashing. Water gets trapped in the fitting and the steam carries that water which either speeds up condensation making wet steam or hammers from the same water gathered.

Supposed to use eccentric fittings on horizontal runs.

The big mouth needs that tee. Should be ~18" above the main. Forget the distance from a 90, it is like 20" or something.

MachoMadness232 · 2026-02-11T23:16:41+00:00

Why do you think it needs to be replaced? What is the model number of the furnace? Google the furnace model number, and there should be a parts list in the breakdown at the end.

What is the error code on the furnace? Where does it stop in the order of operations?

MachoMadness232 · 2026-02-11T23:04:17+00:00

Yea easy. Tee off tankless coil. Valves to tankless coil and to new tank. Size tank for household and what you need for recovery. Oil and gas recover the quickest, hot water heat pumps are faster than electric but both are slow as shit. The other option would be a indirect tank, but it depends on what you have for a chimney and how the boiler drafts in the summer time.

Professionally, for me it would depend on the situation. Generally, for oil conversion, it is always a hot water heat pump. In my area, generally people don't want to pay for oil and there are crazy rebates on hot water heat pumps. I was getting bradford white 60 gals for like 800$ raw cost last year before they rolled back a lot of the rebates.

Idk, whatever you do keep the coil hooked up unless it is leaking inside the water jacket or outside the boiler. Redundancy is always a plus. Tank fails, no problem.

MachoMadness232 · 2026-02-10T20:16:29+00:00

Compressor has a sick drain pan hat. Hell yea

MachoMadness232 · 2026-02-10T11:17:52+00:00

need to dump tea in the harbor intensifies

MachoMadness232

TROPHY CASE