Condensing Verses Non-Condensing Tankless Water Heaters

Condesning tankless

As tankless water heaters become more and more popular the number of manufactures and models are increasing.  A tankless is also referred to as an on demand water heater and as you would expect there is no storage tank on these systems.  Using a more powerful burner a tankless can heat water instantly removing the need for the storage tank.  Although it uses more fuel while heating water it uses absolutely zero any other time, this results in an average of 40% fuel savings over a conventional tank that always keeps your water hot.

On the newer side of things are the condensing tankless water heaters available to home owners now.  These units use two heat exchangers.  The first is primarily used to heat water to your desired temperature.  The second is smaller and located near the top of the unit where the exhaust gases are used to preheat the incoming water.  Using this normally wasted heat in the exhaust bumps up the efficiency of a condensing tankless to 95% or better.

A conventional tankless doesn’t take advantage a second heat exchanger and thus the exhaust gases are much hotter and actually require special venting materials.  This can sometimes add to the cost of installing a tankless.  Whereas your condensing tankless utilizing that second heat exchanger significantly reduces exhaust temperatures, this allows contractors to use less expensive venting materials.

In general for Canadians a condensing tankless works a little better. Preheating the incoming water (which is cold during our winters) allows the tankless to throttle down its gas usage when only a little hot water is needed. Yet, when a high demand appliance requests a lot of hot water the tankless has more than enough power to supply the request. See the recommended Canadian tankless installers and tankless systems.

A condensing tankless cools the normally hot exhaust so much that moisture actually builds up inside the heat exchanger.  Moisture and steam are by-products of combustion and this is a very normal result.  As water clings to the side of the heat exchanger it builds up until it starts to drip down, this water is acidic due to combustion; the water has a pH between 3 and 5.  Rheem has a buffer tank built into its tankless systems to neutralize the condensate.  Rinnai has an external system that buffers this excess water.  Other manufactures have different systems, if you’re interested in any particular one give us a call.


To Conclude condensing tankless water heaters are incredibly efficient (up to 98%), and use inexpensive venting material saving on installation costs.  A condensing unit is more expensive to purchase but prices start to even out when purchasing exhaust materials for a regular tankless.  The choice is yours with regards to which system you feel best fits the needs of your home.

If you have any further question don’t hesitate to ask us

Tankless And Water Heater Servicing In Toronto

Water heaters

If you own a tankless it is important to service your system.  A tankless is designed by engineers to have, first and foremost, the heat exchanger and internals scrubbed with a mild acid (vinegar).  The vinegar reacts with a buildup that occurs in all pipes and watercourses (scale and lime deposits) effectively eating it away and clearing the heat exchangers and pipes. This scale acts as an insulator significantly reducing the transfer of heat to water. Engineers have also taken many precautions to ensure that internals and parts of a tankless have as few wear points as possible.  This has increased the lifespan of a tankless water heater to over 20 years!

Direct Energy and several other large companies that rent water heaters are trying to reduce the tankless emergence.  Currently if you’re renting a conventional water heater the system is designed to have a lifespan of around 10 to 12 years.  After this point the water heater will have significant buildup inside severely reducing its efficiency.  The thing is that none of these companies will push you to replace your system since you are the one paying the gas bill and it only affects your homes energy consumption.

What Can You Do?

That’s easy, call the company your renting your water heater from.  They will tell you the buyout costs and the age of the water heater you have.  If the system isn’t very old I would recommend you keep the water heater until it reaches its operational lifespan (10-12 years). If your system is already quite old you may simply need to schedule a removal with your water heater rental company. Then start getting quotes for a tankless system.

Once that new tankless is installed make sure you take care of it, have it flushed once every two years at the minimum (or flush it yourself).  A flush is simple preventative maintenance that will ensure your system makes it past the expected 20 year lifespan while maintaining its 98% efficiency rating!

Tankless Water Heater Service Valves

Toronto and Area Tankless Services

Service Valves on a Tankless are Important

The service valves on a tankless are essential for cleaning the insides of your tankless.  The valves allow an easy method of changing the incoming and outgoing water from one source to another.  Why would you need this feature? Well your tankless is designed to last more than 20 years and this requires that the scale and lime buildup that forms on the inside of the system is flushed or cleaned out.  The scale forms fastest in situations where water is rapidly heated, so the heat exchanger is the primary location of buildup.

It is not mandatory that these service valves are installed but any good contractor will have included them in the price and if you have a tankless you probably have some already.

The Service Valves Use

Cleaning your tankless requires you to shut the fuel source down, unplug the unit, switch the incoming and outgoing water over with the service valves.  Then you can simply hook up some hoses to the in and out ports on the service valves and pump vinegar or some acidic solution though the tankless.  The acid eats the scale and restores the tankless to its original efficiency.Toronto and Area Tankless Services

Scale buildup quickly reduces the efficiency of your tankless by significantly slowing the transfer of heat to water. 

So if you have a tankless tank a quick peek at your system and see of your contractor or installer included the service valves.  If not, don’t worry they can always be installed after the fact.  Give us a call and we can install some and flush your tankless at the same time.

Service Valves Specifications

  • 3/4″ union connections
  • Colour coded handles and unions
  • Staggered connection points to easy access and installation
  • Forward facing purge/flush ports ease routine servicing
  • Purge/drain hose connection port and cap
  • Full port, quarter turn valves

Ontario Water Hardness Levels

An instant hot or tankless water heater is extremely efficient.  The system relies on its advanced heat exchanger to quickly heat up water.  Scale and Lime tend to build up faster when water is heated, so to combat this problem a tankless is usually installed with flush valves, which allow vinegar to be pushed through the system dissolving the build up and returning the tankless to its original efficiency level.  This build up is exponentially increased as the grains or water hardness increases in communities and towns throughout Ontario.

Hard Water Causes Inefficiency

Below is an extensive list of Ontario cities and the corresponding water hardness that is present in the water supply.  The higher the number of grains the harder your water is, which, in turn produces more scale and deposits in your water heater, on shower heads, around faucets, and so forth.  A conventional water heater will become much less efficient with time in a hard water situation, and it can’t be cleaned. For this reason we recommend a tankless system that can be cleaned with a vinegar solution, restoring efficiency.

Quick Hard Water Exercise:

  1. Lookup your city and see if you have hard water
  2. Think about how old that 40 gallon hot water tank is in your house
  3. Know that in on average at 7.5 grains of hard water a regular tank loses 2% efficiency a year to due scale build up
  4. That 2% doubles to 4% at 15 grains and so on…..
  5. After you do the math a tankless that is able to be cleaned of all scale becomes very economical


City Hardness (grains) Population
Almonte 17.5 2805
Amhurstburg 6.5 6060
Ancaster 19 6718
Arnprior 12.2 8663
Aurora 17 see Newmarket
Azilda 12 1403
Barrie 9.5 41990
Beamsville 15.6 3864
Belleville 6 34391
Bracebridge 2 5304
Brampton 24.2 58571
Brantford 24 42053
Brockville 7.5 11302
Burks Falls 10 1200
Burlington 9 47562
Carleton Place 5.5 4956
Cayuga 120 905
Chatham 13 19874
Cippawa 8.6 N/A
Clifford 15 660
Clinton 13.2 2136
Cobalt 4 461
Cobourg 7.5 7234
Cochrane 18 2474
Collingwood 4.5 9632
Copper Cliff 2 N/A
Cornwall 7 19290
Craigment 4 N/A
Delhi 18 2819
Deseronto 8.4 1314
Dryden 3.5 5900
Dundas 17 10320
Dunnville 21 3830
Elmira 29 390
Essex 33.4 3658
Etobicoke 8 109153
Fonthill 15.6 2495
Fort Williams 1 N/A
Galt 22 930
Gannonoque 7 3759
Goderich 5.5 4808
Grimsby 8 6821
Guelph 22 30652
Hagersville 30 2055
Haileybury 2 1243
Hamilton 7.5 147943
Harrow 49.8 3112
Hanover 13 3915
Hawkesbury 2 5300
Hespeler 26 550
Ingersoll 24.4 4269
Iroquois Falls 4.5 2005
Islington 16.2 20137
Kapuskasing 6 3490
Kemptville 16.4 6130
Kenora 4 9929
Kingston 7.5 37776
Kirkland Lake 3 4712
Kitchener 40 87480
Lansing 21 N/A
Leamington 14 17253
Lindsay 8.5 27220
Listowel 13 9907
London 25 149133
Lucan 13 N/A
Lucknow 16.4 977
Meaford 12 2978
Merritton 8.5 N/A
Midland 8 16268
Mitchell 16.2 1907
Matawa 5
Mount Forest 25 2937
New Liskeard 16 3306
Newmarket 10.5 53915
New Toronto 8 see Toronto
Niagara Falls 8 29250
North Bay 1 24960
North York Twsp. 18 173099
Norwick 14 1220
Oakville 7 34364
Orillia 10 19999
Oshawa 7.5 38796
Ottawa 3 181258
Owen Sound 15 20688
Paisley 19.5 829
Paris 20 2984
Parkhill 14 1145
Parry Sound 4 3020
Pembroke 2 15357
Penetanguishene 7.5 see Midland
Perth 4 5596
Peterborough 5 40913
Picton 7 2265
Port Arthur 6 N/A
Port Colborne 7 6291
Port Dover 13.2 N/A
Port Elgin 38.4 1852
Port Hope 7.5 5553
Prescott 7 3553
Preston 17 620
Renfrew 2.5 12221
Richmond Hill 17.2 72717
St. Catharines 7 40750
St. Mary’s 22.8 1475
St. Thomas 11.5 29300
Sarnia 7 38869
Sault Ste. Marie 3 29847
Scarborough 8.5 155061
Seaforth 17.5 1496
Shelburne 12 N/A
Simcoe 12 16900
Smith Falls 5 6904
Stratford 30 14604
Strathroy 17.5 5543
Sturgeon Falls 2 3134
Sudbury 2.5 53168
Tavistock 30.4 1893
Tecumseh 7.8 5953
Teeswater 32 616
Thorold 8 5848
Tillsonburg 12 8925
Timmins 2 19055
Toronto 7.5 319202
Trenton 14 6120
Twin Province 17.5 N/A
Uxbridge 15.4 3533
Walkerton 8.8 2651
Wallaceburg 6.5 5822
Waterloo 28 see Kitchener
Welland 8 19258
Weston 10 9448
Whitby 7.5 19750
Windsor 6 72436
Woodbridge 16.2 11770
Woodroffe 22.5 N/A
Woodstock 2.5 26041

It’s always a good idea to have your water tested to determine not only water quality but water hardness and this list should be considered just a rough guide.

Tankless Flushing 139$

Flushing your tankless is essential to maintaining its high efficiency rating. A tankless flush will remove all of the scale and lime that has built up on your heat exchanger saving you money and helping the environment. Give us a call today to schedule your next service.

Scale builds up fast inside a tankless as the water hardness of a certain area increases.  Check out this chart of water hardness in cities around Southern Ontario and see how much your water heater is at risk for scale buildup.

Having a clean tankless is the most important factor in keeping your tankless at its highest efficiency level. If you have had a tankless installed already by a reputable company you will have service valves, but if you paid a bargain basement price for your tankless the contractor probably omitted the valves to save money (they can still be added to the system after the fact). These valves isolate the heat exchanger allowing it to be flushed or cleaned of lime scale, calcium, and general buildup which acts as an insulator preventing the water from absorbing heat more readily. A tankless flush with a vinegar solution will dissolve the buildup effectively reviving the factory level of efficiency.

We at Go Tankless only use food grade citric acid or food grade phosphorus acid to flush the inside of your tankless. This is a potable water system and if any contractor says they use a solution of CLR or some other highly acidic poisonous solution do not let them near your house! The last thing you want is to be introducing poisons to your drinking system.

Our tankless flushing service covers most of Southern Ontario, give us a call and we can schedule a flush for your water heater.  A tankless flushing is a quick process and only takes about an hour.