Tankless waterheater - Page 2

BRad704 · 01-06-2010, 07:32 PM

but you still had to run an new hardline back from the "T" to the pump, right? Just trying to make sure my mind has all this right....

**havasu** · 01-06-2010, 07:40 PM

On my new tankless water heater, I did have to run a return line back to the tank, but the recirculating pump needs nothing more than the return valve, which is about 7" long. It's a 4 way valve. You connect your cold and hot water supply line on one side, and connect included cold and hot water supply lines to your sink. This creates the valve necessary to push the tepid hot water back through the cold water line, creating a recirculated system.

BRad704 · 01-06-2010, 07:42 PM

Quote:

Originally Posted by havasu

On my new tankless water heater, I did have to run a return line back to the tank, but the recirculating pump needs nothing more than the return valve, which is about 7" long. It's a 4 way valve. You connect your cold and hot water supply line on one side, and connect included cold and hot water supply lines to your sink. This creates the valve necessary to push the tepid hot water back through the cold water line, creating a recirculated system.

OOOHHHHHH>...... NOW i get it...

But what happens when you want instant cold water? you have to wait?

**havasu** · 01-06-2010, 07:45 PM

If I want instant cold water, I go to the refrigerator! All kidding aside, the cold water line never got hot, just luke warm for a bit. I still have a hard time understanding how or why it worked so well, but it was a great addition.

BRad704 · 01-06-2010, 10:12 PM

I guess its not like there is 160F water in both your pipes from start to end... you are just forcing the hot water (now semi-hot from sitting in the pipes) around to the cold line. Thus getting water from your water heater further into the hot pipe by the time you turn on the hot water... I think I could like with lukewarm water to brush my teeth, as long as my shower didnt take 5 minutes to get warm anymore.

**majakdragon** · 01-08-2010, 06:07 PM

You really need to do your homework before going tankless. Not all units are the equal or the same quality. I hear good things about Rinnai. Know what the warranty requires. Some need to be installed by a Pro. I read about people increasing the water line size to 3/4" before and after the unit since most have 3/4" inlet and outlets. Not sure if this would be kosher as far as a warranty. Realize that many Plumbers will install them, but will not do maintenance or repairs since they are state of the art units. If you have hard water or high minerals, forget tankless. The tubing in them is small and will clog easily. As for circulating pumps, I think the best thing is a point-of-use switch. Installed at the furthest fixture from the heater, you push the button before using the water and the pump activates. This means the pump is not continuously running while no water is being used. Just some thoughts.

**havasu** · 01-08-2010, 07:17 PM

You are very correct about doing your homework when deciding on a tankless heater. The one I just purchased has a built in filter, which can be cleaned in 5 seconds. So far, we have run both showers and the washing machine all at the same time, with no loss of heat, just a little loss of pressure. I just received my first natural gas bill today since the installation, and is down about 15%. With the freezing Southern California weather we have been experiencing (got down to 45 degrees once last month, woo hoo!) it is still hard to judge accurately.

**SilverBack4Jack** · 01-13-2010, 04:51 AM

one of the most common misunderstandings is that people think a tankless heater provides instant hot water. Not true! Your tankless heater supplies you an endless supply, until the power goes out, of hot water. I dont recommend the electric ones as most require more power upgrades to feed a whole house than most people in a residential home. Not to mention you could blow dry your hair at the meter base it will be spinning so fast. Also one of the big benefits of a tankless heater is you dont pay to heat water that you are not using while you arent home, or in a no flow situation. I would think a circulating system would cause the heater to fire more than needed which counteracts the whole heating process causing it to heat more than what is needed. It could be done but just doesnt seem cost effective. I will have to look into this setup to be sure so dont hold me to it.

Grundfos makes a retro-fit style recirculation system as the other guys are describing that is cheaper than a tankless heater and I have heard several good reviews.

Grundfos USA

Hope this helps. I dont claim to be right just my $.02

**havasu** · 01-13-2010, 05:15 AM

The circulating pump timer is broken down to 15 minute segments. I have my pump turn on twice a day, when hot water is needed. This is good for people who shower at the same time of the day, or wash dishes at a certain time. Yes, if a shower is needed when the pump is not activated, then you will wait about 2-3 minutes for hot water.

**SilverBack4Jack** · 01-13-2010, 01:08 PM

Thanks havasu. I didn't realize you were running a timer on your recirc. Makes a little more sense to me now. Basically it just comes on twice a day to try an accomodate the user at That pre selected times each day. Not a bad idea. Still not over heating a lot of water.