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Jeff
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join:2002-12-24
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Jeff

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[Plumbing] Indirect HWH Replacement Question

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burner/boiler
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HWH -
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replacement gasket area
Hi,

I'm getting a lot better at being a home-owner over the last 6 years, but there are still things above my knowledge that I don't mess around with. That line of thought brings me here.

I have oil heat, and it's a "The New Yorker" burner. I have an indirect water heater called a "Smart 50". I am not the original owner of either, as both were here when we purchased in 2008.

For the last 9 months or so, I've had a problem with the pressure release valve of the oil burner dispensing some water into the bucket. Enough where every 7-10 days in the coldest months I have to go down and empty the gallon (or so) of water. I pay about $200/yr for a contract with my oil company (who I actually like) to come and address whatever problems come up. They have done work on the burner/boiler as needed, and since they installed the HWH in 2006, they have looked at it from time to time.

Deciding to get a jump on the water issue before the cold weather really sets in, I called them to check out this ongoing issue. Within the last year, they have replaced the boilers expansion tank, pressure release valve, and pressure regulator. Issue remained. The other day I had them come here. The gentleman was here some time testing and putting gauges everywhere. Once he found nothing wrong with the burner, he checked the HWH. He said he found the pressure to be slowly increasing...a few pounds every 15-20 minutes and that was a result and/or cause of the water leak. Forgive my lack of knowledge of this stuff - he said it a lot better than I could do here, but he essentially said that as the HWH pressure goes up, it hits a point where it feeds back into the boiler and the boiler's pressure release valve kicks off, and boom, water in the bucket. And that inside the HWH there is some type of leak.

Hot water in the house is generally fine. Street pressure coming in is about 85psi. We have no plumbing problems except for items that have wear and age on them.

They're recommendation is to to replace the HWH with a "Bock 50". $2,500. They also recommend replacing the plate and gasket on the boiler - $450.

I have no problem paying for repairs that make sense and will only benefit us. I have two small children (3 years old and 10 days old) and I need to do what is best. At the same time, shelling out $3,000 is not something I do without careful consideration. I have attached some photos.

Do the recommendations make sense? Thanks in advance for all of your help. I really appreciate it. I'll do my best to answer whatever questions you may have.
LittleBill
join:2013-05-24

LittleBill

Member

increasing water pressure is not because of a water heater, either a water regulator or cold water fill is failing somewhere and causing the pressure to increase

did he explain how a new water heater will fix a pressure issue?

i worked on a similar system where the pressure relief valve on the water heater was dumping out water.

ended up being the main house regulator, which was slowly increasing over time, till it reached about 130psi when the relief valve started flowing

Jeff
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join:2002-12-24
GMT -5

Jeff

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He did explain it, but for me to explain it back here, a day later won't work out so well. He basically said that there are two "tanks" inside the one HWH. One is likely leaking, and causing some sort of flow back into the boiler, resulting in the boiler discharging the water.

The HWH is not currently - nor has it ever routinely - discharged water. The pressure valve got stuck open once, and that was remedied several years ago.

I'm not aware of any pressure regulator on my main line in existence. Are you suggesting to put a regulator on to get that 85psi down to 65psi or something like that?

shdesigns
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Stone Mountain, GA
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shdesigns to Jeff

Premium Member

to Jeff
I have had a similar issue, it was the pressure regulator for the house. They can be hard to find. Mine was buried in the garage ceiling. Usually the first or second thing the main line to the house goes to (one spigot is before my regulator.)

My reg was almost 30 years old. The city has been increasing their pressure lately, now up to 140PSI. So the reg could have been leaking before.

It could be the expansion tank has lost its air charge. If it only leaks when the boiler is heating the water, then that may be an expansion issue.

A pressure gauge would help. I picked up one for $13 from HomerD. You can put it on the drain valve of the tank. If you run something then shut it off and the pressure creeps up, that points to a dirty regulator. Mine was $70; there is a rebuild kit for it but that was $50 so not much sense fixing the old one.

If the pressure goes up when the boiler is heating the water, then that points to an expansion issue.

djrobx
Premium Member
join:2000-05-31
Reno, NV

djrobx to Jeff

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to Jeff

Regulator example
Pressure regulators around here seem to have a 15 year lifespan. When they fail, the water pressure increases. Mine had increased to 120PSI because of the failed regulator!

Check where your pipes come into the house and look for something that's kind of like a bell with an adjustment bolt on top. They're not that big.

-- Rob

Jeff
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Jeff

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I'll look for the house pressure regulator, but I have never seen one. The main water supply to the house comes in 15 feet to the right of the oil burner and I haven't seen anything like a regulator there. I'll take a look, but I've never noticed one. The only regular I've seen is on one of the pipes that connect the HWH to the boiler. This regular was replaced back in the spring.

shdesigns See Profile, my guy seemed to have put two pressure gauges on the HWH to test pressure. One was the street pressure, coming in at that 85-90psi that I mentioned. The other pressure gauge hooked up to the HWH at the same time seemed to measure the internal pressure of the HWH. It was this one that was slowly creeping up, a 1lb or two every 30-45 minutes.

Could a house pressure regulator be located outside? I live on Long Island. My main water pipe comes into the house a foot up the wall of my basement, and then extends at some depth underground until 5 feet off the edge of my property, where there is a round small manhole cover. I've seen inside there once - the water pipe is a good few feet down into that hole. I wonder if there could be a pressure regular there, on my side of the meter? Would that be possible? I only ask because I'm in this part of my basement a lot because of the main water ball valve is there, and my outdoor water spigot, and my sprinkler supply line - and I've never noticed a regulator for the main house supply, but I will look again.

If I forget to say it, thanks so much for the help so far. If I could go back and do everything over, I'd immerse myself in electrical, plumbing and architecture work. It's a skill set that everyone needs and it's incredibly frustrating when you're trying to understand stuff you don't know anything about, all while potentially having to write checks.

PSWired
join:2006-03-26
Annapolis, MD

PSWired

Member

Guys, OP has stated that the pressure regulator and expansion tank for the heating circuits has already been replaced. The relief valve that's leaking is the boiler relief, not the domestic hot water tank relief (according to description, not bucket location in photo). A leaking heat exchanger in the DHW tank is an entirely plausible explanation for this, since the higher pressure (60+) domestic water in the indirect tank will equalize with the heating water loop which is normally at ~20 psi. This will eventually saturate the expansion tank and trip the relief valve. Whether this is actually what's happening in OP's scenario, I can't say. But it's definitely plausible.

Also, that coil block off plate looks nasty. Cleaning it up and replacing the gasket would probably be a good idea.
PSWired

PSWired

Member

Also, it looks like there are isolation valves for the indirect tank's heating loop. Turning both of these off for a while will confirm or deny whether the tank is the cause of the pressure creep problem.

Jeff
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Jeff to PSWired

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said by PSWired:

Guys, OP has stated that the pressure regulator and expansion tank for the heating circuits has already been replaced. The relief valve that's leaking is the boiler relief, not the domestic hot water tank relief (according to description, not bucket location in photo)

You are correct. It is the boiler relief that collects water. Sorry, I didn't realize the picture didn't show it. I have buckets under the relief for both the HWH and the boiler. It is only the boiler's relief that has the water in it from time to time. I didn't realize it wasn't shown in the photo - my apologies.
said by PSWired:

A leaking heat exchanger in the DHW tank is an entirely plausible explanation for this, since the higher pressure (60+) domestic water in the indirect tank will equalize with the heating water loop which is normally at ~20 psi. This will eventually saturate the expansion tank and trip the relief valve. Whether this is actually what's happening in OP's scenario, I can't say. But it's definitely plausible.

Ok, I think I understand that. Thanks.
said by PSWired:

Also, that coil block off plate looks nasty. Cleaning it up and replacing the gasket would probably be a good idea.

I agree. It's looked nasty for a little while. I'm having that work done immediately.
LittleBill
join:2013-05-24

LittleBill to PSWired

Member

to PSWired
said by PSWired:

Guys, OP has stated that the pressure regulator and expansion tank for the heating circuits has already been replaced. The relief valve that's leaking is the boiler relief, not the domestic hot water tank relief (according to description, not bucket location in photo). A leaking heat exchanger in the DHW tank is an entirely plausible explanation for this, since the higher pressure (60+) domestic water in the indirect tank will equalize with the heating water loop which is normally at ~20 psi. This will eventually saturate the expansion tank and trip the relief valve. Whether this is actually what's happening in OP's scenario, I can't say. But it's definitely plausible.

Also, that coil block off plate looks nasty. Cleaning it up and replacing the gasket would probably be a good idea.

i don't think anyone is disagreeing with you, i think we trying to save the op 2500 bucks first to make sure it is in fact the cause

that also can easily be tested by waiting until the water is pouring out. then turning off the house water supply and breaking open a hot water tap, if the water stops coming out of the boiler relief then you have proven this is the issue

PSWired
join:2006-03-26
Annapolis, MD

PSWired

Member

Yep, that would be a good test too, if the relief valve is leaking fast enough to tell that it stops when the house water supply is shut off. It sounds like it's a pretty slow leak, though.
Shady Bimmer
Premium Member
join:2001-12-03

Shady Bimmer to Jeff

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to Jeff
When you indicate 'pressure regulator', do you mean the fill valve for the boiler or a domestic potable water supply regulator upstream from the boiler?

Your boiler should have a combination pressure and temperature gauge or a pair of gauges for temperature and pressure. What does your pressure gauge on the boiler typically indicate? (Note it may not be accurate but this is a starting point)

It is possible there is a leak in the domestic hot water tank allowing pressure to bleed into the boiler loop, or it could be possible the fill valve is not fully closing. Note that you should not bleed the domestic hot water pressure while the boiler loop is pressurized, as this can cause failure that would result in leakage. The domestic hot water pressure in the tank should always be above the boiler loop pressure.

If you can shut off the feed (temporarily) to the boiler and monitor the pressure as well as watch for flow from the relief valve this can help identify if the fill valve is the problem. If you still have a pressure increase then the indirect hot water tank is more likely the issue, but if the pressure remains stable (with no flow from the pressure valve) then it is more likely the fill valve is the problem.

PSWired
join:2006-03-26
Annapolis, MD

PSWired

Member

Reading the discussion, Jeffrey appears to have had the boiler fill valve replaced. It also looks new in the first picture.

Looking at the pictures, there are isolation valves for the DHW tank and the boiler fill. These can be used to provide 100% assurance of which component has failed.

I take issue with the claim that depressurizing the DHW tank while the boiler loop is pressurized will damage it. There's a 60PSI pressure delta between the two pressure zones during normal operation. Having 20 pounds in the boiler loop while the tank is atmospheric shouldn't hurt anything.

The (real?) reason you don't want the boiler pressure higher than the domestic pressure in the tank is that if there's a leak, it will contaminate your DHW supply with boiler loop water, which is nasty.

Jeff
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join:2002-12-24
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Jeff

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I just want to give some closure to this thread. I had scheduled my plumber come here to handle some related & unrelated issues that I wanted addressed, and while he was here I had him look at the HWH. I explained the situation, mentioned some of the comments here...and he basically finished my sentences with respect to what company #1 said and what the suggestions were here. And after a little while working with it, he confirmed that the HWH has an internal leak and it's feeding back into the boiler, and the boiler is is then releasing the pressure into the bucket. I can't properly reiterate word-for-word what he said but after some time of diagnosing, he confirmed that the HWH has a slow leak internally causing it to feed back into the boiler.

While unfortunately it's not the cheapest solution I was hoping for, it is what it is. My plumber is recommending a different brand (not Bock) but I think he said Heat-Flo. He said he used to use Superstor, but had some issues with them he didn't particularly love. He's coming in a few hundred dollars less than company #1 for parts+installation.

I'm not familiar with any of the brands, and I have no particular preference. Anything immediately glaring about either brand?