Water heaterrelief valvedripping

Up here a high velocity heating system is forced air and heat exchangers, smaller ducts carry the same amount of air at higher pressure. They are making a come back, they were popular in commercial high rises once upon a time, but dropped because they were less efficient and more troublesome. Not sure why they are coming back now, except maybe everyone forgot?

T&Prelief valvedischarge pipe

The home I’m purchasing has a Takagi tankless water heater but does not have a temperature/pressure relief valve or a discharge line. We asked for this to be added and the sellers told us that per the codes for tank-less hot water heaters (California) a pressure relief valve nor a discharge line are needed. Is this true? If so, is it still a good idea to have one installed or does that fact that the heater is tankless make these items not necessary?

The relief valve doesn’t necessarily need to be near the heater, although most competent installers will generally place it relatively close to the heater.

I’m starting to see these more frequently, usually coupled up with a holding tank and a high velocity heating system. They always have relief valves.

T&Prelief valvedripping

Well I installed quite a few 100% Electric Tankless Water Heaters and never once put one on it. All were inspected and installed in accordance with the manufacturers instructions. The electric models move water based on turning on the faucet, the elements heat the water as they pass thought the chambers and no pressure was every in the unit…nothing to relieve so to speak.

T&Prelief valvewater heater

The home I’m purchasing has a Takagi tankless water heater but does not have a temperature/pressure relief valve or a discharge line. We asked for this to be added and the sellers told us that per the codes for tank-less hot water heaters (California) a pressure relief valve nor a discharge line are needed. Is this true? If so, is it still a good idea to have one installed or does that fact that the heater is tankless make these items not necessary?

Yes and no They both deal with the problem of water expansion. Though I understand what you mean.(just had to get off post.)

http://www.homedepot.com/p/Rheem-EcoSense-4-0-GPM-Max-Flow-Rate-240-Volt-13kw-Electric-Tankless-Water-Heater-RETE-13/202514583#specifications

Good post Jeff. Tankless water heaters are subject to the same type of failures that tank type water heaters occasionally suffer from. tagaki install.jpg472×520 24.8 KB

T&Pvalvevs pressurerelief valve

http://www.homedepot.com/p/Rheem-EcoSense-4-0-GPM-Max-Flow-Rate-240-Volt-13kw-Electric-Tankless-Water-Heater-RETE-13/202514583#specifications

W5 investigates cases where brand-new HVAC systems aren't working properly, with some homeowners finding that their homes are freezing on one floor and feeling tropical on another.

T&Pvalve

The home I’m purchasing has a Takagi tankless water heater but does not have a temperature/pressure relief valve or a discharge line. We asked for this to be added and the sellers told us that per the codes for tank-less hot water heaters (California) a pressure relief valve nor a discharge line are needed. Is this true? If so, is it still a good idea to have one installed or does that fact that the heater is tankless make these items not necessary?

A relief valve is absolutely necessary with any type of water heating device. A combination temperature/pressure relief valve is only required with storage-tank type heaters.

Agreed and even Mike Holmes knows that, as they did one show on this superb High Velocity System. Worth watching for sure.