Reddit reviews Watts Premier Instant Hot Water Recirculating Pump System with Built-In Timer

You need one of these. It will keep the water hot at a distant tap. It also cuts down on wasted energy heating water that eventually just get cold anyway. Insulating the hot water supply line to the bathroom will help too.

Hot Water Recirculation Pump

It's worth it.

Or just get a standard tank and one of these:
Watts 500800 Instant Hot Water Recirculating System with Built-In Timer, Easy to Install https://www.amazon.com/dp/B000E78XHG/ref=cm_sw_r_cp_api_i_8kdwDbZR6E70C

Works quite well for me. I set it up to a smart home plug so it is only running when someone is home.

You guys need a hot water recirculating system. Easy to install and not too expensive.

I installed one of these recirculating pumps a few years ago for the same reason.

It has a built in analog timer, but I just set it to always on and use a smart plug to handle the time schedule.

This solves your problem.


http://www.amazon.com/Watts-500800-Premier-Water-Recirculation/dp/B000E78XHG/ref=sr_1_1?ie=UTF8&qid=1412538958&sr=8-1&keywords=hot+water+circulation+pump

You need one of these. Easy to install and hot water FAST!

http://www.amazon.com/gp/aw/d/B000E78XHG?vs=1

A couple hundred bucks plus install. Something like this. We have one and it is nice. The the shower heats up in seconds.

A hot water recirculator might be a better option for you. I dont think anything like that exists, or at least I have never heard of one.

https://www.amazon.com/Watts-500800-Recirculating-System-Built/dp/B000E78XHG

http://www.homedepot.com/p/Hot-Water-Recirculating-System-with-Built-In-Timer-500800/100426993

Basically just cycles the water through to keep the hot warm

If you want to go radical, run a hot water recirculator loop to the sink and back to the water heater. a la Hot Water Recirculating System with Built-In Timer This provides rapid hot water response. Then insulating the whole loop reduces energy loss.

Every tank style hot water heater I have seen or heard of will heat the water, store it, and maintain a temperature. Getting cold water from a hot water line (for some short time) is usually indicative of just cooled water sitting in the pipe between the point of use and the tank.

I think something is wrong with your tank if you have to run the water for 20 minutes before getting hot water. Or perhaps the tank is very far from the shower?

But assuming a working hot water heater, I recommend something like this be installed under the closest sink to the shower. It will pull hot water and pump it into the cold water line. If you set it up correctly on the timer, it will keep the call for hot water set to an optimal time for you (20 min before you wake up). It should keep newly heated water in the hot water pipes between the sink and the tank during the time you set. So you shouldn't have to run the shower long to get hot water, just long enough to clear the cooled water between the sink and shower.

https://www.amazon.com/dp/B000E78XHG/

The downside is it could impact the water in the house for drinking. Because tanks can collect calcium and other minerals, there could be a higher density of this water in the cold water line put there by the recirculating pump. Just something to think about and research a bit.

1. Water recirculation set to when you will be showering. Something (like this)[http://www.amazon.com/gp/product/B000E78XHG/ref=pd_lpo_sbs_dp_ss_1?pf_rd_p=1944687762]
   
   
2. Clean your shower heads with CLR. You may have flow issues and when before it only took 1-2 minutes to heat up now it might take 5-6. If the bathroom sinks can get hot water(eventually) this is likely the cause. I had one of the EPA regulated 2.5GPM shower heads(standard since mid 90's) on the other side of the house, it took around 6-7 minutes to get heater. I drilled out the regulator and bumped it up to around 5gpm, so now it only takes 2-3 minutes and the pressure is way better.
   
   
3. Turn up the temperature on your hot water heater. You may just have really bad insulation so need more heat to get there.

Maybe some kind of hot water circulation system, so you always have hot water when you turn the faucet on. Most of them seem a lot more complicated than that though.
http://www.amazon.com/Watts-500800-Recirculating-System-Built-In/dp/B000E78XHG

I'm going to advise against this completely because it's not going to work, unless I'm completely misunderstanding what you wrote.

The water needs to be constantly circulating or it's going to get cold. If it only circulates for x time after someone opens a tap, they're still going to have to wait for the new hot water to get to the faucet.. and then the extra circulation will continue after they shut off the water.. which is just wasting energy since nobody is actually using the water.

It will be: open tap - wait for cold water to get hot - shut off tap after getting hot water - hot water fills the domestic hot lines, and then cools off because nobody is using it anymore.. and that seems to defeat the purpose completely?

You either need a small pump that is constantly circulating the water or, probably the best bet, is buying a small insta-hot for whatever location you want hot water. If you want it everywhere.. then try: something like this? http://www.amazon.com/Watts-500800-Recirculating-System-Built-In/dp/B000E78XHG

I have no experience designing systems for residential, but I make a living designing plumbing for industrial/commercial/superconductor/hospitals, etc.. so I don't know jack about who makes decent quality systems for the home.

Assuming you mean increasing the volume of water coming from the faucet, then yes. The reason that you'll get cold water from your hot tap for a while is that the water heater is usually pretty far away from the sink. Even if the pipe between the two is well insulated, if you don't use the tap for a while the water sitting in it will cool down. By opening the faucet more, you're moving the old water out of the pipe faster and getting hot water from the heater faster.

If you have to wait a long time for this to happen, you're letting a lot of water go to waste. This can be solved by getting a circulator pump. When installed it pumps water from the sink end of your piping through a return line and back into the system right before the heater. This moves hot water from the heater up to the sink without wasting any.

On the other side, getting colder water would most likely be moving room temp water out of the pipes and getting to water that was sitting in your well or underground piping from the city.

Edit: I should write faster.

Edit Edit: This is one of the pumps I mentioned.