Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.
indirect water heater replacement - project scope
lemesi
Member Posts: 26
Hi all,
I'm a complete amateur, aside from browsing these forums over the past few months and talking to various plumbers in the course of getting estimates.
I currently have a Weil-McLain WGO-3 boiler (10 years old) and a 41-gallon Amtrol Boiler Mate WH-7P (I forget how old, but significantly older than the boiler). The Boiler Mate is producing somewhat less hot water than it used to and a technician believes it to be nearing the end of its life. Therefore, we have decided to replace it pro-actively. I am obsessive about things like this and I value maximum efficiency even if that comes at a price. Since I have the luxury of my current system still working, I am taking some time to do things right.
I don't exactly know the history (was my grandparents' house), but my current setup seems to be plumbed a bit unconventionally based on what I've seen here on these forums, and it is certainly less beautiful than some of what I see here. In particular, the water heater is plumbed into what appears to be a drain valve at the bottom of the boiler. But this setup has been trouble-free for the past few years of living here.
In the spirit of getting the best, I have decided on a 53-gallon Viessmann 300-V as a replacement. It looks like our boiler should be sufficient for this, though the piping needs to be upgraded to 1". I understand that Viessmann is expensive and fully expected to spend a few thousand dollars to get it done right.
However, I recently got a quote from another guy who is very focused on doing things right. He is offended at the current plumbing and he wants to expand the project scope to include:
So the questions:
1) Is the current piping truly going to be problematic for the Viessmann 300-V water heater?
2) Is the current piping going to cause me trouble down the line in other regards, including maintainability?
3) Any other thoughts about my existing plumbing and how to do things "right?"
I'm a complete amateur, aside from browsing these forums over the past few months and talking to various plumbers in the course of getting estimates.
I currently have a Weil-McLain WGO-3 boiler (10 years old) and a 41-gallon Amtrol Boiler Mate WH-7P (I forget how old, but significantly older than the boiler). The Boiler Mate is producing somewhat less hot water than it used to and a technician believes it to be nearing the end of its life. Therefore, we have decided to replace it pro-actively. I am obsessive about things like this and I value maximum efficiency even if that comes at a price. Since I have the luxury of my current system still working, I am taking some time to do things right.
I don't exactly know the history (was my grandparents' house), but my current setup seems to be plumbed a bit unconventionally based on what I've seen here on these forums, and it is certainly less beautiful than some of what I see here. In particular, the water heater is plumbed into what appears to be a drain valve at the bottom of the boiler. But this setup has been trouble-free for the past few years of living here.
In the spirit of getting the best, I have decided on a 53-gallon Viessmann 300-V as a replacement. It looks like our boiler should be sufficient for this, though the piping needs to be upgraded to 1". I understand that Viessmann is expensive and fully expected to spend a few thousand dollars to get it done right.
However, I recently got a quote from another guy who is very focused on doing things right. He is offended at the current plumbing and he wants to expand the project scope to include:
- replacing all near boiler supply and return piping
- new zone headers
- Grundfos circulation pumps with flanged ball valves
- all new electrical wiring and controls
So the questions:
1) Is the current piping truly going to be problematic for the Viessmann 300-V water heater?
2) Is the current piping going to cause me trouble down the line in other regards, including maintainability?
3) Any other thoughts about my existing plumbing and how to do things "right?"
0
Comments
-
I would leave everything as is and I would not put in a 53 gallon tank unless you really need it. That is overkill and less efficient. A tank full of water sitting there loosing heat. The bigger the tank the more standby loss.
Where is your expansion tank located? Didn't see it
4 -
I would install a SuperStor SSU45 and leave everything else alone. Everything you have is common and can be replaced as needed.
1 -
I definitely wouldn't be replacing it at all if I weren't afraid it was going to fail at some point in the not too distant future. We plan to end up with at least three full bathrooms after we do a renovation in a couple years, while 41 worked for my grandparents, it now seems borderline. Plus part of it is that there isn't a Viessmann in that size, I suppose. I definitely see your point about heat loss otherwise. They also make an insanely large 79-gallon tank if I recall correctly, so I thought I was already being conservative.EBEBRATT-Ed said:I would leave everything as is and I would not put in a 53 gallon tank unless you really need it. That is overkill and less efficient. A tank full of water sitting there loosing heat. The bigger the tank the more standby loss.
There is one. It's behind the boiler. You can see it a little bit in the first and last photos.EBEBRATT-Ed said:
Where is your expansion tank located? Didn't see it0 -
I really am hoping to go with the Viessmann unless there is some reason it isn't practical due to my current setup or if somebody tells me a reason why something else is better. My preference for Viessmann is primarily because, in my understanding, they use better stainless steel than most and are known to last the longest. For me replacing it is not only an expense down the line, but an inconvenience. I'm also a big fan of German engineering. Having lived there for a while, my opinion is that they are very good at making things like this. I'm fully willing to pay the big bucks for the best and I'll gladly put in a Viessmann boiler in 20 years or whatever when my Weil-McLain dies. That said, the reason for these questions is I do want to make sure I'm not replacing parts that don't need replaced. And I'm just not qualified to make that judgement.
My philosophy in life is to use things up completely, and when that time comes where replacement is necessary then buy nothing but the best. From everything I've seen, buying a Viessmann might very well mean never buying another.0 -
Before you get a water heater have your water checked. Make sure your chlorides and PH fit the water parameters in the installation manual. When Reading the new warranty terms for Viessmann it says cleaned and inspected every single year. The cost to preform that maintance and cost of gaskets to do that is going to add up quick to keep a lifetime warranty valid. That said do it for the tank and not the warranty. They are solid and robust tanks. I have had fittings fail on them after 8 years, but unsure of cause to be fair. Every time I have opened my tank it looks brand new. Probably because of the large surface area of the coils. You need to remove the pricing per sire rules. Where are you located and have you thought about adding a back up heat pump water heater. That would add that free ac /dehumidification in the summer and leave your current set up for the winter when boiler is on. That would enable you to shut down the boiler during the summer. That is a good back up when the boilermate fails. Then see if you turn up aquastat on current boilermate you get the hot water you need if you do, then add a mixing valve on the output from the boilermate to keep domestic water supply temp low and just run up tank temp. Use the boiler in the winter and heat pump water heater in summer. Then when the boiler is going to be replace have a new IDWH installed at the same time. Of course unless the boiler mate fails before that because of a leak. When comparing IDWH efficiencies except for Tank insulation I think it is all about the efficiencies of the boiler.
3 -
That's a good idea. I actually do get my water tested yearly, as it's well water. Everything is normally good, though quite hard. I will take a look back through my recent results and compare with Viessmann's requirements.heathead said:Before you get a water heater have your water checked. Make sure your chlorides and PH fit the water parameters in the installation manual.
It's good to know that about the warranty, though I'm not looking at Viessmann for the warranty so much as the reliability. I plan to be pretty proactive with maintenance, so it's likely not a problem. Somehow my grandparents got decades out of the Boiler Mate with zero maintenance, but I wasn't planning to try to replicate their luck.heathead said:
When Reading the new warranty terms for Viessmann it says cleaned and inspected every single year. The cost to preform that maintance and cost of gaskets to do that is going to add up quick to keep a lifetime warranty valid. That said do it for the tank and not the warranty.
What are "sire rules?"heathead said:
You need to remove the pricing per sire rules.
I'm located in CT.heathead said:
Where are you located and have you thought about adding a back up heat pump water heater. That would add that free ac /dehumidification in the summer and leave your current set up for the winter when boiler is on. That would enable you to shut down the boiler during the summer. That is a good back up when the boilermate fails. Then see if you turn up aquastat on current boilermate you get the hot water you need if you do, then add a mixing valve on the output from the boilermate to keep domestic water supply temp low and just run up tank temp. Use the boiler in the winter and heat pump water heater in summer. Then when the boiler is going to be replace have a new IDWH installed at the same time. Of course unless the boiler mate fails before that because of a leak.
That's a very interesting idea. I did consider all options at first when I began this exercise, and I looked at heat pump units. It was going to be fairly expensive, iirc, because I would need 220V run across the basement and I have no floor drains so would need to pump water up and over to the sink. I guess the main reason I didn't go that route though was that I was concerned I wouldn't like the recovery after becoming accustomed to the indirect tank. This idea of using it as a backup had never occurred to me. I guess I'm not too keen on having two at the same time, due to space constraints. Though it is technically possible if one were on each side of the boiler, which I imagine makes plumbing much more difficult/costly?
Also, in my understanding it's actually good for the boiler to fire up in the summer as opposed to sitting unused. Is there truth to this?
Another problem with this scheme is that the Boiler Mate is likely going to fail long before my boiler. The aquastat is already nearly maxed out and there is some corrosion on the bottom as if there has been a slight dribble. I've been told that the 10-year-old Weil-McLain boiler has a long time, likely decades, left in it. Of course if you have other experience with those boilers, I'd been interested to hear when you think it will fail.0 -
The piping looks fine; upgrading to 1" will certainly help with recovery time.
You can't beat a Viessmann indirect. I've had a horizontal 50 gallon one in my basement for 13 years; flawless. Knock on wood, we've never had one leak. They are my go-to indirect.
Here is one we're installing now, 79 gallons:
8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour
Two btu per sq ft for degree difference for a slab1 -
If you undersize the tank you will know. If you oversize the tank you have just lost a little bit in cost of the tank and standby losses, the loss difference is likely very little with a well insulated model.2
-
I was just looking through the Viessmann warranty information and my past water test results. I'm totally good on the water test numbers.
One thing though: What exactly is a "Certified Installer?" There are a handful of people here in CT who install Viessmann products regularly and other licensed plumbers who will install whatever you want. Is there some specific Viessmann certification I need to be asking about?0 -
What exactly is a "Certified Installer?"Good question. My guess is that it is someone who has attended at least one of their classes in Rhode Island.
Find out who the Viessmann rep. is in your area and ask them. The wholesaler might even know.8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour
Two btu per sq ft for degree difference for a slab0 -
So direct question following up on the original post-
Is there any problem with the way the indirect tank is currently plumbed to the drain valve at the bottom of the boiler? Will this cause any trouble with a higher-end boiler?0 -
Check on the Bradford White indirect.
I buy them at FW Webb. Lifetime warranty. Although it is just a glass lined steel tank.
I've has a 316L tank fail in 7 years. Doing a little research found that many stainless tanks fail in my area. My chlorides are low. Water is 9grains hardness. The tank pinhole'd almost no deposites on the coil, I flush it 2x a year.
Vie$$mann is an excellent product, just may not be 100% worth the money compared to the competition.Serving Northern Maine HVAC & Controls. I burn wood, it smells good!0 -
It looks like currently the water heater is 120v controlled.
If your WGO came with the Hydrostat 3250 Plus then reconfigure the control wiring to take advantage of its options.0 -
Some here may not agree with me, but I would consider putting another Boilermate in. You have to consider the fact that the existing one has lasted a long time for a reason. I've seen the Boilermate outlast a lot of more expensive tanks with no maintenance. I'd switch to 1"piping and and leave everything else as is.
2 -
Maybe scale on the exchanger pipe? ..... check to see if you can thermal shock to clean the coils.
I would wait until you remodel and match what you need -- with oil fired boiler the recovery is quick. Bigger is not always better.
I replaced my Buderus indirect a few years ago at one of my places ... installed in 94. New Buderus SS
My new house being built now has a Viessmann boiler -- so I matched it to the 300 EVIA SS tank ... 42 gallon
2 -
Unfortunately, with the other one showing signs of dribbles, I don't want to risk another few years on it. I'm in no hurry to do this job but I think I'm going to be in a jam if it actually fails. Right now I have time to think about this and do it right while still having the luxury of hot showers.TAG said:
I would wait until you remodel and match what you need -- with oil fired boiler the recovery is quick. Bigger is not always better.
How many users do you have? Viessmann makes it a little hard to compare side by side, so how does the 300-W (I guess that's what you have in the 42-gallon?) compare overall to the 300-V, other than the size? I see the pipe sizes are different, but otherwise they seem generally similar.TAG said:
My new house being built now has a Viessmann boiler -- so I matched it to the 300 EVIA SS tank ... 42 gallon0 -
We have 4 people ,,, you did not mention that the current tank is dripping .... where?
The 300 EVA I is the white SS tank that matches the boiler --- it's been out a few years. The other tanks are silver. I'm not sure if it has anything different vs the silver ... it has a strange heat exchanger coil inside. It also has a better recovery number than the Buderus SS tank ... my guess it's simply a factor of the Viessmann having a greater coil length.
Bigger tanks take longer to recover -- your winter water temp is another issue. DHW is a strange calculation .... a smaller tank with fast recovery works just like a big one for most uses at lower cost/ heat loss.1 -
I can't see too well what's going on underneath. I can see some mild corrosion in several places, but the guy that came out indicated that there had been some dribbling, maybe where the aquastat goes in, if I recall correctly?TAG said:We have 4 people ,,, you did not mention that the current tank is dripping .... where?
I very much like the idea of going smaller if I can have four people comfortably using it. It's very difficult for me to calculate my needs, partly because I'm an amateur learning all of this by reading stuff, but also because of unknowns. For instance, what do you expect my incoming water temperature is during the winter in New England coming from a well? It's also worth noting that my boiler is rated at 115,000 BTU, which if I recall correctly is a bit undersized for the 53-gallon variant. So maybe the 42 is a good option, plus honestly I prefer the look of the white.TAG said:
Bigger tanks take longer to recover -- your winter water temp is another issue. DHW is a strange calculation .... a smaller tank with fast recovery works just like a big one for most uses at lower cost/ heat loss.
0 -
Your 115K boiler would be well suited for any of the Viessmann indirects, all the way up to 119 gallons. Instead of taking half an hour for the 42 gallon tank to recover, it would take an hour. Along with the new indirect, get a control that has a feature called "DHW Priority" which turns off your house heating until the indirect is recharged.
I've found that there are at least two kinds of people when it comes to DHW capacity in their homes. Those that can manage hot water usage to capacity constraints and those that never want to run out of hot water. If you're the latter, get the 79 gallon tank if you have the room. You will never have to worry about having enough hot water again.8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour
Two btu per sq ft for degree difference for a slab1 -
If you have a smaller boiler you may need a bigger tank. The tank needs to store more energy if the boiler is smaller to produce the same mount of hot water.
3 -
Is that calculation just a guess off the top of your head, or is there math behind it? I believe you, but I'm having trouble seeing how to get there from the spec sheets.Instead of taking half an hour for the 42 gallon tank to recover, it would take an hour.
Yeah I've been thinking about this. Also, what do you think about thermostatic mixing valves? I was thinking it seemed like a great idea, so I could run the tank hotter. But I've talked to a couple plumbers who didn't seem to think much of them. Also, what's up with a plumber telling me he doesn't believe in heat traps? Normally those are universally considered to be a good idea, right?Along with the new indirect, get a control that has a feature called "DHW Priority" which turns off your house heating until the indirect is recharged.
I guess I'm personally in the middle, but leaning toward the first group. I'm into the efficiency for the environmental aspects. Plus I like the idea of the tank taking up less space and spending less money. The problem is that my wife is unhappy about how she currently runs out of water and I want my visitors to not run out of water, etc. You guys have me torn between the 42 and and 53 now.I've found that there are at least two kinds of people when it comes to DHW capacity in their homes. Those that can manage hot water usage to capacity constraints and those that never want to run out of hot water. If you're the latter, get the 79 gallon tank if you have the room. You will never have to worry about having enough hot water again.
0 -
If you follow this chart, it would take 33 minutes to heat the 79-gal. tank from 40F-140F and 45 minutes to heat the tank from 40F-176F with a 119,000 BTU boiler.
The chart is basically the same for a 53-gallon tank, so it will take 22 minutes and 30 minutes respectively.
Thermostatic mixing valves are great for increasing the capacity of a water heater, but I only use them where necessary. It's another thing to go wrong. I'm a minimalist.
Heat traps work if you have hot water migration, but again, I don't install them as migration is not usually a problem.The problem is that my wife is unhappy about how she currently runs out of water and I want my visitors to not run out of water, etc.There's a real easy way to solve those two problems.
8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour
Two btu per sq ft for degree difference for a slab2 -
You said your grandparents somehow got decades out of the Boilermate with very little maintenance. I had the same thought when I replaced our 24 year old electric water heater with an indirect. After reading tons on the subject and this type of stainless vs that type of stainless I decided the actual track record for a glass lined tank made a darned good argument. I installed a 40 gallon Bock indirect set at 140 degrees with a mixing valve so 125 degree water goes to the faucets. The boiler is limited to 70k btu with DHW priority. The supply temp for DHW is 160. Recovery after a couple showers is 12 minutes. When we've had guests, five back to back showers did not exhaust the tank. Everyone had hot water. The Bock has a smooth large bore coil. I piped with 1 inch copper.1
-
Hot water is a strange animal .... think of a typical 40 gallon tank hot water heater. In a one bathroom home they typically work well -- even with many people using them with some self control. They often only have 26k burners. I built a log cabin out in PA many years ago and back then you could get a Bradford White unit that they called fast recovery -- it again had one full and one 1/2 bath. Even with six people (guests) ... I can't remember too many Issues.
My one sister-in-law is always a problem wherever she goes -- so that's my only memory of problems.
As you increase bathrooms the potential for drawdown increases -- I was concerned and posted on my current build about my small Viessmann boiler 60-70k and the 42 gallon with two bathroom. When you look at the specifications -- the key is that first drawn down. You want enough in the tank for that first use .... a smaller tank will reheat faster and be ready for the next cycle. The larger tank will still be reheating.
That's why you are now having boilers with small tanks -- like the 222 Viessmann. The 26g is enough for many and it reheats quickly.
With the potential of three bathrooms running at once -- you have to do the calculations ... that's why I say -- wait.
1 -
I just called Viessmann and they told me that any licensed plumber will suffice.What exactly is a "Certified Installer?"Good question. My guess is that it is someone who has attended at least one of their classes in Rhode Island.0 -
I just called Viessmann and they told me that any licensed plumber will suffice.An indirect installation is pretty straightforward. Just make sure they follow the installation instructions; pump selection comes to mind.8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour
Two btu per sq ft for degree difference for a slab0 -
I've read some places that many water heaters have heat traps built in. This isn't the case on the 300-V, is it?0
-
FYI: My current project is the result of a major fire in 2012 .... Delays ... fighting Insurance, township (twice), fired builder ... false start .... had to walk away from it for almost two years (my sanity) . The new builder (fantastic) started almost a year ago now ... it's almost done. So when the HVAC people finally fired up the Viessmann 200 boiler a couple weeks ago -- it came up with a date in 2013. It had been sitting in the box since some time in 2014.
When they called Viessmann for some support ... Viessmann gave them a case number and said they would honor the warranty from that install date.
1 -
This research is still ongoing, as I have time. I've decided that I am a bit offended about Viessmann's routine service rule to keep the warranty active. I do intend to maintain whatever I buy properly, but their requirement strikes me as a way to get out of paying. Plus it is a costly endeavor over time.
In this vein, I am doing a bit of a sanity check, looking back at some other models I've previously considered. One brand in particular that I've been interested in is HTP. I'm trying to understand how they are positioning the SuperStor Ultra Max vs. the SuperStor Pro. Does anybody have any insight into the tradeoffs between the two?
Also, does anybody have any other suggestions for an indirect heater that meets the following criteria (I'm not that price conscious)?
1) somewhere between 40 and 50 gallons
2) stainless steel
3) super long lasting (doesn't necessarily need a lifetime warranty)
4) super efficient
5) no unreasonable rules to keep warranty active
0 -
Look at weil-mcclain and maybe triangle tube as well. The weil-mcclain i believe allows higher chloride content than the htp while remaining in warranty.1
-
So does anybody know the difference between the SuperStor Ultra Max and the SuperStor Pro?0
-
I ended up doing nearly this. I actually went with the MSSU-45N, the "Ultra Max." The installers did pretty much leave the existing configuration alone. They used 1" pipe for most of the boiler supply and return, but then downsized to 3/4 near the boiler. I wasn't so sure about this, but they assured me the flow was fine this way. Also they installed a mixing valve on top, which seemed like a good idea.Dave T_2 said:I would install a SuperStor SSU45 and leave everything else alone. Everything you have is common and can be replaced as needed.
The performance seems great after having it for 24 hours now. We've been trying to abuse it and so far we haven't encountered any shortage of hot water. However, I have noticed that there seems to be a lot of heat migrating up the cold water input pipe. The warmth goes up several feet and I can't even hold my hand on the pipe within the first 8-12 inches or so. Even worse, because of this, it seems to be hot on the cold side of the mixing valve. They talked me out of putting a heat trap on the input. Was this a bad idea? How much heat migration is normal?
1 -
Heat trapping is the best way to alleviate the heat migration.
You can put some fiberglass insulation on all the piping to keep the heat in.Serving Northern Maine HVAC & Controls. I burn wood, it smells good!0
Categories
- All Categories
- 86.3K THE MAIN WALL
- 3.1K A-C, Heat Pumps & Refrigeration
- 53 Biomass
- 422 Carbon Monoxide Awareness
- 90 Chimneys & Flues
- 2K Domestic Hot Water
- 5.4K Gas Heating
- 100 Geothermal
- 156 Indoor-Air Quality
- 3.4K Oil Heating
- 64 Pipe Deterioration
- 917 Plumbing
- 6.1K Radiant Heating
- 381 Solar
- 14.9K Strictly Steam
- 3.3K Thermostats and Controls
- 54 Water Quality
- 41 Industry Classes
- 47 Job Opportunities
- 17 Recall Announcements