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

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

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

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?

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 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

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

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

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!

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

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 buried 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)

Please disregard. After a days worth of research and another source pointing to the owners manual, I have found that where I have set it to work is actually exactly where it should be. Reference page 59 for the specs. I will back flush the system this evening as it is a suggested maintenance.

Link to the manual:
http://burnham.com/pdf/V8H_io.pdf

Please let us know if that works for you. Good luck, Tom

Good for you Brian... ;)

In fact the aquastat should be set at 190F for winter and sometimes you can get away with 160F or so for the spring/summer months!

You will need to make adjustment to the mixing valve, of course.

Thanks for the update...

MARK

Thanks, mark.

Question for you... I back flushed the coil last night. It was mostly clear and it took about 20 seconds of flow before I noticed a slight "dirty" look to the water. This lasted all of perhaps 5 seconds before going back to clear. Does this sound about right?

I only took one shower since doing the flush, and the improvement in hot water output just by simply having the aquastat set correctly made any improvement from the flushing unknown to me...

What did you flush the coil with?

Just regular water from the cold feed at standard street pressure. From what I read in the I/o manual, that is all that was necessary for maintenance. It was my understanding that the acid solution is only needed when there is a mineral build up/blockage?

Come to think of it, that could have come from the run of the old copper pipes.. I had to run the flush from about 10 feet of copper prior to reaching the coil by daisying the hot/cold from the washer machine... whoever installed the boiler didn't put a faucet (barb?) inline after the coil, only before it in the cold feed.

Exactly, if mineral build up, you may want to consider an acid wash... otherwise, sounds like you have a handle on things!

MARK

Thanks for the confirmation/help on things, mark. It is much appreciated. This is going to be my last stupid question that I can't figure out... if I don't see scales on the upper right corner... how so I give you positive ratings?

Hmmm...

That may explain the decrease in ratings lately... ;) I'm using a new "SKIN" and it shows a scale for rating me. As you clearly pointed out... no scales on the old skin.

I'll have to review that.

Thank you for taking the time to ask... appreciated!

MARK

Brian,
Do not have an answer but have similar issue.
Have 1964 American Standard Arcoliner (167,000 BTU/hr)with General Fittings (Rhode Island tankless coil, GPM is not legible) with 30 gal aquaboost storage tank.

Just bought house in Boston suburb.

Unlimited hot water it seems except lower flow than needed in upstairs bath.
Kitchen, bathroom in basement have 2 gpm hot and cold. Shower unknown because of single control valve but good pressure and hot water.
Ktchen sink, 1st floor bath and slop sink in laundry have the same. No issue.
Upstairs bath has approx 1gpm hot and 4 gpm cold at the tub filler. Sink has approx 1gpm hot and 2 cold.
In order to shower, hot must be on full with 1/10 turn of cold.Two separate valves. This is after I choke the cold at shutoff in basement so that faucet flow at sink is severely reduced when toilet is flushed. Back flushed with the dime in the sink faucet with no increase in flow to tub. Barely usable as long a no one else turns on hot water in house. Tub fills real slow with hot and shower head is adjustable water massage. It works great in basement. Supply line into tankless looks like 3/4' with 1/2" out.
Cold water run to bathroom is same size. I understand lower flow at the sinks because of the reduced connections by why the low flow to the tub. Entire basement has finished plaster ceiling so I am trying "black box" box approach before opening up. Is it possible that the tankless coil is clogged. Quote to replace is $1300. When I removed the faucet stem get good initial pressure but presure/flow drops off immediately. Tankless mixer set at 140 deg with circulator controlled by thermostat in storage tank set at 120 deg
Any feedback would be helpful
Thanks
FMH