Two quotes for combi boilers for radiant and DHW

ThinkpadUser7

It sounds like starting in 2030 California might not allow new gas appliances to be sold. If say, 10 years from now, my combi boiler has an issue that isn't practical to repair, I assume I would need to switch to something electric. Would that be a fairly simple replacement? Or does it bring up a strong case for making the jump to electric now?

WMno57

ThinkpadUser7 said:

It sounds like starting in 2030 California might not allow new gas appliances to be sold. If say, 10 years from now, my combi boiler has an issue that isn't practical to repair, I assume I would need to switch to something electric. Would that be a fairly simple replacement? Or does it bring up a strong case for making the jump to electric now?

Great question! Very difficult to answer. We have another discussion here that delves into Air to Water heat pumps. Those are uncommon. Your copper in slab is at end of life. Air to Air is the majority of the market.
https://forum.heatinghelp.com/discussion/195676/ducted-chilled-water-fan-coils-with-ashp-hydronic-systems
How close is your home to being a teardown? Not saying your home is a dump. In Hinsdale, IL your home would be a teardown, even if it were perfect. I'm not familiar with your hood.
You need a crystal ball that predicts future government policy and viability of new technology. If you find said ball, rent it out to Mary Barra of General Motors. That knowledge would be worth millions. Then you can just buy a new house.

hot_rod

You are in a good climate for A2whp, do you have a suitable location to mount one? https://idronics.caleffi.com/magazine/27-air-water-heat-pump-systems

ThinkpadUser7

WMno57 said:

How close is your home to being a teardown?

The house is 100% a teardown. A new buyer will almost certainly be demolishing it and building something entirely new.

ThinkpadUser7

hot_rod said:

You are in a good climate for A2whp, do you have a suitable location to mount one? https://idronics.caleffi.com/magazine/27-air-water-heat-pump-systems

There's a cement patio area on the other side of that boiler closet door, but aesthetically it wouldn't be ideal to look out at that from our living/dining room windows. We'd probably want it mounted around the corner from that patio on the side of the house (~20 feet away from boiler closet door). My other hesitation would be due to fan noise as we're already annoyed by the droning sound of what I assume is our neighbor's heatpump fans that are near the other side of the property line.

ThinkpadUser7

I do wonder at what point holes/slots in an exterior door is considered adequate for intake air. This is how my current room has been getting air for the past 75 years. Notice the open slots in the door plus there's a fan/opening up high but I don't think that fan runs anymore.

hot_rod

There is a calculation for the square inches of air that you need based on the burner sizes.
Between the fan opening and the lower opening it looks like it has been plenty.

If it is easy, pull the air from outside the room, directly to the boiler. I’ll bet that old flue will accommodate exhaust and intake air with a concentric kit. It may only be a. 2 or 3” pvc vent. Much easier to deal with than grills on the door.

I much prefer exhaust out the roof. Your neighbors may too.

Close lot lines can be a non starter for heat pumps, although some are brands pretty quiet.

A heat pump can give you heat, hot water, and chilled water to do some cooling.

ThinkpadUser7

How concerned should I be about the removal process for (what I've been told) is an asbestos flue? A couple of the places I've contacted have mentioned that they won't dispose of it, but most places haven't mentioned it at all.

If not carefully removed and the area cleaned, is there a danger if asbestos gets into intake of new system?

ThinkpadUser7

I had an on-site visit by the IBC place today to answer my questions. This is the first time they've come out to see the space in person. Overall it didn't leave a great impression. There was a lot of push back about using anything other than the IBC SFC, and I didn't really get satisfactory explanations for various questions.

At this point I'm leaning a bit more towards the Viesmann/NTI place, despite the concerns related to the atmospheric pressure boiler install. I'm not really sure I get the concern considering we can't see the rest of the space, what the door is like (or even if there is a door).

ThinkpadUser7

Sorry for all the questions but I have another one.

I have this pressure gauge hooked up to my current system near the expansion tank:


Normally I see the pressure of the gauge vary between around 5 and 15. There is apparently a way for the system to fill with new water if the pressure drops but I have no idea if it works. Note that this gauge is part of the return line and nowhere near the pump.

Today the IBC guy saw the pressure drop from 15 to 5 and then go back up, but said the mechanism to add water to the system didn't seem to be doing anything. So he didn't really understand why the pressure changes were occurring. He did increase the pressure of the expansion tank after noticing it was at 8 psi.

Anyways, I'm curious if anyone has any insight into what was happening?

hot_rod

You need to find out if the system is connected to a water line with a fill valve that is turned on. That should be fairly easy to do?

The gauge needle will go up if a fill valve allows water into the system, 5-15 psi for example, easy enough.

The pressure will increase as the water temperature increases, did the burner kick on?

The needle could move up if the pump kicks on, if it is on the discharge of the pump.
If the gauge is on the inlet side of the pump, it could drop from 15 to five when the pump is powered up. So a number or combination of things may have been going on during the visit?


You really need to sort out the fill valve question first. If it is open, turned on, it could be masking a leak in the tubing, if so this whole adventure comes to an end, in my opinion.

ThinkpadUser7

hot_rod said:

You need to find out if the system is connected to a water line with a fill valve that is turned on. That should be fairly easy to do?

I've had multiple radiant heating specialists comment that it seemed to be setup that way (and turned on), though they have also expressed that they see no sign it's actually filling. Not sure how they're determining this... lack of noise?

hot_rod said:

The gauge needle will go up if a fill valve allows water into the system, 5-15 psi for example, easy enough.

The pressure will increase as the water temperature increases, did the burner kick on?

The needle could move up if the pump kicks on, if it is on the discharge of the pump.
If the gauge is on the inlet side of the pump, it could drop from 15 to five when the pump is powered up. So a number or combination of things may have been going on during the visit?

I'm pretty sure the burner and pump were already on and stayed on during this period.

hot_rod said:

You really need to sort out the fill valve question first. If it is open, turned on, it could be masking a leak in the tubing, if so this whole adventure comes to an end, in my opinion.

This gets back to the issue of pressure testing. To pressure test, this old equipment needs to be disconnected? Can this be done in a minimally disruptive way? If it turns out there are massive leaks then it might be awhile before I'm able to figure out and execute on the next steps, so having our old heating system functional again might be important.

A different place that came out said they were very doubtful we had a leak based on our low water usage, which averages 2 CCF per month. But idk. Seems like there are lots of theories and no real answers without an actual test.

hot_rod

Exactly, you need to somehow get some stable data. Determine what conditions and how the pressure is changing as you stand in front of the assembly.

First I would buy a new 30 psi pressure gauge, rule out a defective sticky gauge.

You do not need to disconnect anything. Some how add water pressure to get to 25 psi. The fill valve if you have one would do this.

Don’t fire the boiler, don’t run the pump check that gauge in a few hours, or longer if you can.
It may drop a psi or two if the water cools in the system.

If it drops 10 psi or to zero and there are no visible leaks in the room,then suspect the pipe in the slab.
I though you had done this somehow?

When the system is running, the pump, the burner, the pressures will change. Expansion of the fluid and the energy that the pump imparts to the water to get it moving, no need to worry about that. The important thing is pressure doesn’t drop and stay at zero , ever.


The amount of or the direction the pressure goes depends on exactly where the gauge connects to the system

The pump causes the water to move by creating a pressure difference. It lowers the pressure on the intake side, and increases it on the discharge side. So gauge location tells you what the pump is doing. The pump adds mechanical energy to the system when it spins, pressure increase is one indication that is happening.

If you want to know more, it’s a deep subject.

https://www.caleffi.com/sites/default/files/media/external-file/Idronics_16_NA_Circulation in hydronic systems.pdf

ThinkpadUser7

The mechanism that's intended to add water automatically when pressure gets low wouldn't do any filling if the heat system (boiler + pump) are off?

There was that place that said they didn't think there was a leak based on my low water usage. I pointed out that I rarely used the heating and the response was that it would still fill when the system wasn't on.

Maybe I should share some more detailed photos...

hot_rod

If it has a typical pressure reducing fill valve that is working, not shut off or plugged up, it will maintain the system pressure accurately 

and it will do this with a small, undetected leak, adding water at the rate it is leaking out. Pressure stays stable 

ThinkpadUser7

So I assume the test steps you posted above should include ensuring the pressure reducing fill valve is shut off?

I'm kind of surprised that none of the places that came out suggested doing this. They all made it sound like the only accurate way to judge was to disconnect everything to test just the slab piping.

hot_rod

Yes, just use the fill valve to get the pressure to 20-25, then turn it off.

if there is an obvious leak in the boiler or piping, then you might isolate the manifolds and pressure test.  But you would need to set up a gauge and valve to get pressure into just the loops.

Either you do that or pay someone to do it.

ThinkpadUser7

I chatted with the person I've used to service my boiler in the past and he suggested doing this to pressure test (I had told him I was fine not having heat for a week or two):

1. Turn off gas to boiler. This was suggested because the pilot light is fairly large for my setup and may influence pressure.
2. Wait a couple days for temperature to stabilize
3. Take note of pressure indicated by gauge and then close fill valve to ensure no new water enters system
4. Wait a week and check pressure again

Make sense?

He didn't say this but between step 1 and 2 I suppose I should also turn off electrical to safety / gas flow unit and pump?

He didn't mention anything about increasing pressure of system before running test, so I'd have to add that step too if it's important.

I might try this myself, but I'll need to ensure I know where everything is located. I should be able to locate the gas shutoff. Hopefully there is one specifically for the boiler that also includes the pilot. I'm not sure how the fill valve / pressure regulator work. I'll try to post photos of the relevant areas tomorrow to get further guidance.

ThinkpadUser7

Ok, I'm attaching some photos below. Do I have the parts correctly identified?
Can you confirm the procedure I should use to do a basic pressure test?

ThinkpadUser7

Here was the full procedure suggested by the radiant heating person who has been advising me:

1. turn off electrical
2. do 90 degree flip of rear gas lever to turn off gas
3. wait two days
4. turn fill valve clockwise as tight as possible
5. take picture of gauge
6. keep eye on gauge for first 1-2 hours to see if it's dropping quickly
7. if not dropping quickly leave it for a few days
8. if still looks ok, release a little water at spigot to get pressure down to around 8 to confirm fill valve isn't doing anything.
9. leave for a few more days
10. check gauge again

If all looks ok, turn system on again with:
1. turn on electrical
2. turn on feed water
3. turn on gas
4. hold down reset button, light pilot light while keeping reset button depressed for ~1 minute

hot_rod

Clockwise increases the pressure on the fill valve. Take it to 20-25psi.

Pump off, gas off watch it for a day. A few psi drop as the system cools is normal. What I look for is a drop to 0 or a very low pressure like 3-5. That would be a warning sign, of a slab leak.

5-8 psi drop I’ve a day or two could be from the system cooling down

ThinkpadUser7

I was about to do step 4 above. The gas (including pilot) have been shut off for over 48 hours.

You mean turning the nut on top of the reducing valve increases pressure on the loop?

ThinkpadUser7

Is it normal for fill valve to only turn about a quarter turn? (or possibly 1/6 or 1/8)
It turns very smoothly but only goes that far. I don't see any change in either position.

Should I try releasing pressure from the spigot? The gauge still shows ~11 PSI.

hot_rod

Loosen the nut, a couple turns then turn the slotted stem. The nut is just to lock the stem from moving once you get it set.
You are pushing against spring tension inside so it takes some force.

ThinkpadUser7

@hot_rod Thanks. At this point I'm still not sure the fill valve is even closable.

Result of spigot test to release pressure:

It started at 11 psi and I released enough pressure to see the gauge drop to 7 psi. I left the fill valve set in its most counterclockwise position ("open"). After 40 minutes it was reading 9 psi and after an hour it was reading 10 psi.

I then released pressure to get it down to 6.5 psi and set the fill valve to its most clockwise position ("closed"). An hour later it was around 7 psi. And an hour after that it is was around 8.5 psi. I'll check it again tomorrow morning.

So it seems as if the closed position is still letting some water through. Could the expansion tank be contributing to changes as well?

I didn't try a wrench on the fill valve because I didn't want to break anything; it goes from smoothly turning to immediately stopped.

Any ideas for what I should try next?

hot_rod

The shutoff valve next to the fill valve doesn’t shut off?

Looks like the fill valve is connected to the hot water line on top of the water heater?

You could shut off the valve that feeds the hot water tank also, if that is the case?

dko

He is tightening the nut on the fill valve to "close."

You do not use the fill valve nut to open and close. You set it at the PSI you want and then you use the shut off valve to close. In your case it's the white handle gate valve.

ThinkpadUser7

dko said:

He is tightening the nut on the fill valve to "close."

You do not use the fill valve nut to open and close. You set it at the PSI you want and then you use the shut off valve to close. In your case it's the white handle gate valve.

When I'm talking about closing the fill valve above by turning it clockwise, I'm referring to the large white (with some red) circular knob:

ThinkpadUser7

hot_rod said:

The shutoff valve next to the fill valve doesn’t shut off?

Looks like the fill valve is connected to the hot water line on top of the water heater?

You could shut off the valve that feeds the hot water tank also, if that is the case?

Yes, after turning the white handle knob in the photo above I still saw pressure raise (heat/pilot/electrical was off for over 50 hours prior)

If I shutoff the water supply for the water heater that would prevent a handful of tiny drops from flowing through the fill valve? The amount of water I needed to release at the spigot to get the pressure to drop from 10 to 6.5 was very small.

hot_rod

The fill valve is not a shut off there is no open and closed position

the wheeled handle valve next to it is the only way to shut it off

If you cannot confirm that valves closes tightly, and the fill valve leaks through, this gets more complicated

Time to get the experience pros back

ThinkpadUser7

Yeah sorry, I guess I was using the wrong terminology. The only thing I've rotated is the white wheeled handle valve in the photo. I have not touched what is labeled as a "pressure reducing valve" or "relief valve" (both are bell shapes in the photo above)

What is the U shaped outer handle on the "relief valve" for? (it's in the up position in the photo)

dko

The pressure reducing valve is the fill valve (it "fills" the system to the set pressure) The white wheeled handle valve is the shut off valve.

ThinkpadUser7

I guess I could do the test by lowering the fill valve to say 6 psi, releasing pressure from the spigot to get it down to 8 psi, and then letting it sit for multiple days to see if it drops to 6 psi?

Though to be honest I'm not sure I have good enough access to the fill valve to feel comfortable doing fine adjustments, so maybe it's time to call in the pros.

ThinkpadUser7

Would it be easy for someone I hire to replace or fix the shutoff valve for the purposes of doing this test?

Or perhaps I'm supposed to use a lot more force with a wrench?

hot_rod

Some how, someway you need to get an accurate pressure test. A new system could go a high as 30 psi so a 25-28 psi test would be a good idea

which is where this  post started🥴

ThinkpadUser7

hot_rod said:

Some how, someway you need to get an accurate pressure test. A new system could go a high as 30 psi so a 25-28 psi test would be a good idea

which is where this  post started🥴

yeah, I know. This started with me trying to figure out what I could test without professional help but we seem to have exhausted that option. I'm not sure there's an easy way for me to increase the pressure beyond the current 11 psi limit.

hot_rod

You increase pressure by lifting this metal hoop on the pressure reducing valve. It basically allow the pressure in the building to bypass that valve, so lift it carefully as you watch the pressure.

Download the manual for more operatinginfo.

ThinkpadUser7

hot_rod said:

You increase pressure by lifting this metal hoop on the pressure reducing valve. It basically allow the pressure in the building to bypass that valve, so lift it carefully as you watch the pressure.

Download the manual for more operatinginfo.

So I should try to build pressure up to 25 psi (by lifting metal hoop on pressure reducing valve) and then seeing if pressure drops? Because the reducing valve seems to be set around 11 psi, I assume no new water will enter system until it gets to around 11 psi?

hot_rod

ThinkpadUser7 said:

hot_rod said:

You increase pressure by lifting this metal hoop on the pressure reducing valve. It basically allow the pressure in the building to bypass that valve, so lift it carefully as you watch the pressure.

Download the manual for more operatinginfo.

So I should try to build pressure up to 25 psi (by lifting metal hoop on pressure reducing valve) and then seeing if pressure drops? Because the reducing valve seems to be set around 11 psi, I assume no new water will enter system until it gets to around 11 psi?

Nothing to lose by adding some pressure. Below 30 psi.

ThinkpadUser7

hot_rod said:

You increase pressure by lifting this metal hoop on the pressure reducing valve. It basically allow the pressure in the building to bypass that valve, so lift it carefully as you watch the pressure.

Download the manual for more operatinginfo.

Unfortunately, lifting that metal hoop does nothing. I feel nothing, hear nothing and see no pressure change on the gauge at any position. I did put the shutoff value in its most open position as well.