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Razprod · Mar 9, 2008, 08:32 PM

Hi, I am new here and have a question about my plumbing. :confused:

I just moved to a new house (to me), its 5 years old. When using any of the faucets in the house it begins with a flow of very hot water, sometimes lasting a minute sometimes going for close to 3 minutes.

Once it goes to cold water it will rotate between cold and hot.

I have replaced the kitchen faucet, since it looked fairly warn out.

Still having same problem, need some help!

:confused:

msk · Mar 9, 2008, 09:14 PM

There seem to be two main reasons for this( either of two). If you have a water heater (also called geyser), check if it has a non return valve at the inlet to it. Many times the hot water returns from the inlet side or if it exists, it may not be working properly.Secondly whether your lines are exposed to hot climate. In hot climate areas if the lines are exposed to direct sun initially the water comes out hot (normally in the day time). Try to check these two first.

Razprod · Mar 10, 2008, 11:49 AM

Thanks for the response,

I had a plumber have a look at the geyser and he said it all seemed OK. I am up in Canada so we are in the winter as everyone probably knows we are under a blanket of snow, so I know that there are no exposed lines to the sunlight that would be heating up the water.

The plumber checked all the mains coming out of the basement and he said they all looked OK. I do have a dishwasher that was here when we moved in and a washer and dryer. I read in another post that those could mix the lines up, but I want to know for sure before I start messing with them.

The faucet in the kitchen had separate taps for hot and cold, I switched it to the single lever faucet as another plumber told me that would be a better fit. The one in the washroom still has separate taps for hot and cold. I checked the lines going to them and they seem to be installed correctly as well.

I just want to eliminate this problem cause my daughter sometimes tries to use the faucets and I don't want her getting burned.

Thanks

massplumber2008 · Mar 10, 2008, 03:34 PM

Razprod... you must have a cross connection somewhere... could be pipes, a bypass with a shutoff that is not shut, or a check valve that has malfunctioned (gotten stuck in open position). Could even be a mixing shower valve or single handle faucet.. but I am not leaning toward that yet.

Do you have a recirculating hot water line in the house? Any mixing valves at outside water faucets or even at the water heater.. And look around for a check valve in the plumbing system.

If need more info. On this stuff, let us know and we will get pictures for you. Talk soon... MARK

hkstroud · Mar 10, 2008, 04:20 PM

Try a process of elimination to isolate the culprit. Since you only have one single leaver faucet, turn off the stop valves and see if the phonomania occurs. Same thing with clothes washer and any other devices that normally have hot and cold available. A dish washer normally only uses hot water. Is your water heater a separate appliance or is it a part of your heating system. Either way feel the cold water input line a few feet away from the heater to see if hot water is coming back up the cold water line while this is happening while cold water tap is open.

msk · Mar 10, 2008, 09:16 PM

There may be more than one options as massplumber2008 and hkstroud have said. Try eliminating faucets one by one by closing the valves and check again. One thing which you have mentioned is that once the hot water goes it rotates between hot and cold water. To me it seems a malfunction of check valve since its difficult to check the malfunction of a check valve. Also you must be a best judge of the layout of piping system try to check if there is any inter connection between hot and cold water lines(I mean a valve)

Razprod · Mar 11, 2008, 11:35 AM

Thanks very much MSK, massplumber2008 and hkstroud. I went through had a look at the hot water tank to see if there were any "additions" of pipes found none.

I could not see the check valve on the water tank, so instead I turned off the cold water feed going into the tank. The cold water pipe was fairly hot so I figured I'd start by turning that off.

I checked all my taps after that and the water flow is just perfect. Now my question is how do I correct this problem?

Would this be something that I would need to call the guys who installed this water tank?

massplumber2008 · Mar 11, 2008, 12:50 PM

Raz... did you just suggest that you shut the cold water shutoff to your water heater OFF and you still have HOT water coming out of the faucets.. If so, you, better call them back because something is not kosher and when it comes to water heaters I just don't mess around.

Get back to us... hate to ask you to repeat yourself.. but I am not sure I read you right... Mark

msk · Mar 11, 2008, 09:33 PM

Dear Razprod
Thanks for responding. From your response it seems that the plumber has not installed a check valve at the inlet to the hot water tank(geyser). This causes the hot water to return back through the cold water line. I think you should call the persons who installed the hot water tank. A check valve must be installed at the inlet to hot water tank(that is cold water line).This is the exactly tha same problem I have also faced. After installing the check valve it was solved. (check valve or non return valve is a small piece may be 2 inch long with an inbuilt safety valve which is fitted in line with the flexible hose or pipe)

massplumber2008 · Mar 12, 2008, 04:12 AM

msk... did you read razprod's last post? I am still waiting for an answer to my question.

The valve you present is not the common valve for backflow prevention on a water heater in the USA. A check valve is also not required or recommended for normal water heater installation. In fact, my code book says "a check valve shall not be installed in cold water line to any water heater, unless approved by the BOARD". If approved, for say a recirc. Line, then an expansion tank shall also be installed. Of course, RAZ is in Canada.. and you never know with them Canadians... ;)

You present a watts 9d backflow preventer.. it is required (by code) to be installed on the cold water line of all forced water heating boilers or steam boilers with automatic feeders installed. It is not that that valve will not prevent backflow on a water heater... it is just not commonly used anywhere that I know of for water heater backflow prevention
(three times the price of a vacuum breaker, too).

For water heater backflow prevention the most common device is a vacuum breaker (see pic.).

When backflow occurs.. say like when a fire hydrant is flushed by fire department, a backflow preventer's job is to allow air into the lines in place of the water in the vessel (boiler or water heater) instead of siphoning/emptying the vessel. It was happening for years... homeowners would come home to broken water heaters/boilers that had emptied (via siphon action.. no BF protection) and then fired empty.. and well.. you get it. Codes changed shortly after.

You do have me curious now though... Raz.. do you have a vacuum breaker on heater... not that will fix this, but absolutely need one... let me and MSK know.. ok?

AND WAITING ON ANSWER TO MY LAST QUESTION... ;)

YOU GUYS TAKE CARE... TALK SOON... MARK

Razprod · Mar 12, 2008, 11:45 AM

Sorry Guys for not being as clear as I thought I was. I do that sometimes...

Massplumber2008, to clarify when I shut off the Cold water main inflow to the water heater it solved my problem.

I had nice cold water flowing out of my taps once the remaining hot water was drained from the cold taps.

Now the both of you talked about the check valve and vacuum breaker. I had a look around the pipe going into the water tank couldn't see anything apart from a single pipe going in, nothing there. I think I'll post a picture of the tank so you guys can see what I am talking about as well.