[Huge29]

We are just in the middle of finalizing house plans and I had planned to have a tankless water heater and use the manablock system as I have neighbors with each and love them. However, more than once I have heard the opinions of plumbers who dislike both of them. I had planned to place the mechanical in a new spot just to reduce the distance of runs (on the side of the house where laundry, master and kids bath) from the manablock and to have the tankless near an outer wall to reduce teh amount of the expensive stainless pipe needed. However, if we go with traditional plumbing (still PEX obviously) and old fashioned water heaters, likely two 40 gallon units.
The opinions against are:
-larger gas line for the tankless and pressure reducers for everything else to not have the higher 2lb pressure, takes longer to get teh hot water.
-manablock-it was a trend, waste of lots of pipe plus way more labor to install (plumber told me to just add a thousand dollars over traditional plumbing), take longer to get hot water, contrary to claims, 1'2" pipe creates way too much pressure drop (also contrary to claims),

Just wanted to collect a few more opinions, clearly the traditional systems on both factors are cheaper, which I like, but being our own design we really want the better options and cost is not that much different. Thanks for your help!

 

[Cooky]

My parents house is a large rambler with water use points a long way apart. During a remodel they had tankless water heaters installed and love them. I think she actually has a tank type water heater still, near the dish and clothes washer at the center of the house, and tankless heaters at the far corners of the house for bathrooms and the workshop. I'm not sure about cost, mom just likes the way they work.

 

[bow_dude]

I am a General Contractor. G C's know a little about everything, but are experts at nothing, so here is my expert opinion (Expert= a has been drip under pressure). Don't install your water lines on an outside wall. Just a good practice incase of freezing. Tankless, (insta hot) work well in office spaces and areas where you do not use large amounts of hot water. They heat by electricity which is expensive in comparison to gas. Should you have a power outage for a few days, which happens sometimes, you will be taking a cold shower. There are pro's and con's to each. I would look at water consumption needs and then decide. Putting a jacket over the water heater can help along with insulating your water lines. Personally, unless there is a really long run from the water heater to the water outlets, I would stay with a water heater. Just make sure it is a fast recovery water heater. That is my $.02.

 

[utaharcheryhunter]

I have 10 years with plumbing experience. I am currently out of the trade, but this is my 2 cents.. I have installed both things that you have mentioned above. So I will start with manablock. The manablock system serves its purpose. Giving you the ability to have individual runs to every fixture in the house, and a shutoff valve to boot. I have changed out several, seen the fittings burst, and in every house I have seen the manablocks installed they all leak!!
Ok, second the tankless waterheater. LOVE THEM!! They are costly up front, but way more cost efficient in the long run. All the tankless waterheaters I have installed have to be directly vented out of the house. I used PVC to run the vents out. The tanks used 3/4 gas lines, but don't use gas more. If you are worried about hot water taking forever, I never had any customers complain. I always thought it was fast.

 

[utaharcheryhunter]

Huge29, I know we have had our differences, but send me a pm or something if you have any questions. Just started getting back into this forum, been a while. I recently got out of the trade back in december. But I still have plumbing fresh on my mind. I also have some good contacts if needed. I have worked for several plumbing outfits, and the last guys I worked with are the best!!

 

[Huge29]

Thanks for the input! PM to be sent promptly.

 

[goforbroke]

I stay clear of a manablocks. I wish I had a tankless water heater. Less monthly cost and never run out of hot water.

 

[Huge29]

I stay clear of a manablocks. I wish I had a tankless water heater. Less monthly cost and never run out of hot water.

That is the way I am leaning. A big issue with manablocs is that the valve seize too. Most of the benefits they claim I dont think would really help in my situation other than turning off all hose bibs, but really not a big deal. On the tankless, those who are familiar with them and have actually used them absolutely love them! The one caveat being that the unit be property sized, the reviews on the more economical units have really poor reviews, so it appears that we will need a 9 gpm unit. I like the condensing units that use the PVC vs the crazy expensive stainless venting pipe. one of my favorite features beyond never running out of hot water (pretty nice feature when you have two washers and three kids who all insist on showering at the same time at night), is that they can be flushed quite easily to remove all of the scale build up vs the traditional method of just waiting for the buildup to slowly ruin the efficiency and eventually rust out teh tank until it leaks.
I think the savings issue is a bit silly personally as my gas bill during the summer is like $14/month most of which is the normal hookup vs actual use charges. i am leaning towards the Noritz, Bosh or Rheem unit with cost no less than $900 minus the $350 Questar rebate and possibly a tax credit.
For those who care, I found that the condensing style tankless not only uses the more economical PVC vs stainless venting, but also can run on the standard 4 oz of gas pressure vs the larger gas line and need for up to 2 lbs of pressure, which creates the need for a reducer at every other appliance, gets too complex. This is the one I like as I begin narrowing it down http://www.amazon.com/gp/product/B008E6LIQ2/ref=s9_simh_gw_p60_d2_i3?pf_rd_m=ATVPDKIKX0DER&pf_rd_s=desktop-7&pf_rd_r=1YDC90482X0GPKES65NC&pf_rd_t=36701&pf_rd_p=2090148982&pf_rd_i=desktop

 

[bowgy]

Huge, that looks a lot like the one I put in at the cabin, I have it on propane not natural gas, we love it, I do have the stainless venting but it is only about 3-4 feet to the outside wall and it is the dual vent where the exhaust pipe is inside the air intake pipe.

One thing is to make sure you put a rodent proof screen on the vent, my plumber didn't an I got a mouse in the tank electronics and ruined the main module, they are quite expensive to replace and mine was in over a year old and past warranty, however I give kudos to Rheem's customer service, they sent me out a new module at no cost....free...nada....not even shipping. So I would recommend the Rheem Branded tankless water heater.

 

[Huge29]

What? Wow, that is impressive, thanks for the info! Sounds wrong, but how big us your unit and how many fixtures does it serve?

 

[jshuag]

How did I miss this post?

I just replaced all of the copper in my House on Thursday with pex. Did it all myself. I used copper headers. They are all connected to an on demand water heater.

It works Great!

2500 sq ft. home. 1 kitchen 2 baths and a laundry room. Started Thursday at 2:30 p.m. and finished Friday at 3 p.m.

Don't go maniblock. I have heard they all leak. But I would recommend an on demand water heater. I love mine.

 

[bowgy]

What? Wow, that is impressive, thanks for the info! Sounds wrong, but how big us your unit and how many fixtures does it serve?

I just have it hooked to the main hot water, the cabin is relatively small, 26' x 36', 2-1/2 bath. Just over 2400 square feet. I guess I didn't know enough to get one with multiple outputs. I can't remember the size but I know that while someone was taking a shower we were able to wash dishes with no problem, the plumber said that both showers could run at the same time with no problems but haven't tried it. Since we are totally off grid at the cabin I haul water and have a 1550 gallon water tank in the basement, so we conserve water as much as possible.

It's mostly a weekend cabin so not too many showers.