How do i increase the temperature of my hot water? I have a burnham furnace with tankless hot water.Thanks!!

Milo Dolezal

Your water heater should have thermostat that allows you to adjust water temperature. It should be set at around 115F.

massplumber2008

Hi all:

If you have a tankless coil on that burnham boiler you will be looking for a MIXING VALVE (see picture) near the connections to the tankless coil at the boiler.

There is a knurled knob on top of most mixing valves that will allow you to adjust the temp. up or down. Move this knob only a little at a time and test after you reset each time as these can be a bit finicky to adjust.

If there are children in the home, please purchase a thermometer and do not allow the water temperature to exceed 120-125F as anything past this can cause severe burns in short time.

Finally, why are you increasing the temp...? Do you run out of water quickly?? If so, increasing the temperature will not fix that...you need other valve and may even need to clean the tankless coil....let me know...O.K??

Let us know if you have questions...

MARK

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weetamoe79

Thank you, thank you, thank you, Mark! I wanted to turn up the temperature as the hot water runs out quickly to luke warm. The tankless was replaced last year and the shower and tub are only two years old. I get plenty of hot water in the kitchen. What are my options for hot water in the bathrooms?

massplumber2008

Hi Weetamoe79:

I understand that the kitchen sink always stays hot...it is a low volume fixture that only delivers 1.5 G.P.M. or less and is usually mixed with some cold water within that 1.5 G.P.M., but I am wondering how the lavatory faucets do as they are also a low volume fixture...? Let me know...

All shower heads are restricted to delivering 2.5 G.P.M. and have been for years now, but if you have an older shower head it is possible that your shower head is delivering 5 G.P.M. or more...that would DEFINITELY be an issue for a tankless coil...new or not!! To check this, look at the shower head and see if you see any tiny print embossed into the plastic..let me know what it says. Tubs can also be a big issue for a tankless coil as they also deliver a large volume of water.

These larger volume fixtures (tub/shower) usually start out strong (hot) but taper off quickly in such a way that you need to adjust temperature...can be very uncomfortable.

It is also possible that the volume of water flowing through the tankless coil exceeds the ability of the coil to heat the water. Here, in compliment to the volume discussion, the tankless coil output cannot keep up with demand. In this case, they make a P-3 valve that reduces the volume but doesn't reduce the pressure...great device (see picture). This valve is installed into the cold water feed of the tankless coil...it may be worth investigating this as this is quick/easy install and has made a SIGNIFICANT difference in tankless coil output form any of my customers... Check out http://www.watts.com/pdf/ES-P3.pdf

You could also have a temperature limiting device in place at each tub/shower valve....would need to know the name brand (kohler, symmons, american-standard, delta, price-pfister, glacier bay, etc...) to tell you how to adjust this (it is under the knob or trim plate).

Finally, I don't think the coil itself is clogged with mineral deposits to the point that it needs to be cleaned (acid wash) as this is 1 yr. old...and hopefully you don't have such hard water that it will ever be necessary.

Let me know more...see what we can come up with here.

MARK

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weetamoe79

Thanks again, Mark! You are a wealth of information. The tub and shower fixtures are symmons. Would HD or Lowes sell the P3 valve or do I need to print out the information sheet and mail?

massplumber2008

Hi all..

Symmons has a temperature limiting screw right under the trim plate (see image)...remove the handle, the plate and the round chrome piece and you will see a small screw almost flush with the valve. If you loosen this screw 1/2 turn at a time you can increase the temperature of the water coming out. If you loosen the screw too much it will leak or even pop out and cause a mess so loosen only a full turn or so...MAXIMUM.

The temp. at your shower should not exceed 112-115F....if it does and you are running out of hot water, as stated, need to try this P-3 valve next ( you can purchase a water thermomemter (range to 200F) at home depot or any plumbing supply company).

I usually install the P-3 valve and set them at #3.5 to start. You may need to adjust this slightly, but try setting at #3.5 first (instructions show how). It is installed in cold water feed as shown at that diagram. It MUST not be installed before the cold water feeds the mixer, but after it and before the cold water feed INTO the tankless coil. The P-3 valve should be available in your area at any plumbing supply company.

Finally, if this fails to help, you may need to install a storage tank system that works with the tankless coil, but for now try the above...let me know how you make out.

MARK

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weetamoe79

Thanks again, Mark! I'll try to adjust the fixtures first, then will install the P3 valve if that doesn't fix the problem. Your input is greatly appreciated!!

massplumber2008

Glad to help...hope it makes a difference for you.

bflooks

This is bringing an old thread back to life, but this existing topic has everything to do with my situation. please bare with me.

have a 5 year old burnham steam boiler with tankless and a honeywell l4006a aquastat. the house sat empty for almost a year prior to us purchasing it last year. since we moved in, the hot water was hardly hot and extremely hit or miss. short bursts, long wait time, etc. etc. etc.

the l4006a was set at 130* with the difference set at 5*. in order to get consistent hot water throughout the house (1 story cape with kitchen and 1 bath), i have to crank the aquastat up to 190*. this allows us to run hot water continuously without having the handles burried at hot with no cold input. the mixer valve is almost completey closed.

i believe the boiler is an hv83 (???) and the l4006a temp goes up to 240*. i know this shouldn't be right since the boiler is kept at near boil just so we can have not water... this is mostly during cold months. during the summer, we can get "decent"hot water output with the l4006a set at 180*.

what am i missing? could it need to be back flushed? i can do that myself. if it needs anything else, i will just wait for medway oil to show up in december for our service contract visit... i would really like to be informed prior to that date though.

any help would be much appreciated.

thanks,
brian (near boston)