I am installing a MHU45LP heater in my cottage. What will I need for the gas hookup to a 100# propane tank and is a regulator required??

It is possible that the problem with your All Pro SPC 150T propane heater could be caused by a faulty gas regulator or pressure switch. The gas regulator controls the flow of propane while the pressure switch controls the temperature of the heater. You may need to replace the gas regulator or pressure switch in order to get your heater running again. Additionally, you could also check for any loose connections or clogs in the fuel line.

Heaters with a large burner needs a regulator that will deliver a large volume of gas at a pressure to suit the appliance, typically 13 inches water gauge from memory. The gas outlet should be a similar diameter to the heater gas inlet.

Small burners can use a smaller capacity regulator but again the outlet should be a similar diameter to the heater inlet.

The choice of whether to use a fixed regulator or an adjustable is optional. Outdoor appliances are better suited to an adjustable regulator.
A really large burner is perhaps better used with an industrial gas regulator, similar to those used with gas cutting/welding gear...

The regulator on the heater probably is not but is probably a device to prevent the heater being used unless the gas pressure is high enough and also serves to prevent air entering the gas line and also serves to arrest flashbacks.

The standard propane low pressure regulator is 14" water gauge but the heater might need a high pressure regulator. The best way to decide which type of high pressure regulator to use, because there are several, is to use an adjustable regulator.

After installing the adjustable regulator the pressure is increased until gas can be heard to be flowing and the heater lit. The regulator should then be adjusted to produce a clean flame of the correct length and then the regulator adjustment locknut should be tightened.

If the heater is to be used indoors it is important to ensure there is plenty of ventilation and the emissions are checked by a gas engineer.

Sure is. You simply need to purchase a to 3/4" to 1/2" Male to female reducer. You didn't mention if your current gas piping is flexible copper, rigid black iron pipe or flexible stainless steel. In any event, get the one that matches your current gas piping. If all of your other gas appliances require an individual regulator, then you'll need one for the tankless water heater. If in doubt, contact your propane provider.

Hope this helped answer your question and provide a solution.

I think what you have is a 100 Lb tank, that holds 40 gallons of propane. If that's,the case, it would be acceptable. IF the tank is placed Outside the garage 3 ft from any doors or windows: The gas line is a minimum of 1/2" diameter; the heater is permanently mounted to the wall (at least 18" off the floor); there is an accessible, inline gas shutoff valve within 2 feet of the heater and you have a properly sized tank regulator. You do all that, and you'll reach the minimum code standards that are required.

Hope this helps you make the right decision.

Rich

could you have gotten a natural gas tank by mistake? it would have larger orfices and allow more gas than you need propane has more B.T.U.s than nat gas and requires a smaller orfice
chack with your gas co.good luck.

Propane exist in a liquid state when it is under pressure in a propane cylinder. When the valve on the propane cylinder the pressure on the liquid is reduced and the propane reverts back to gas state.

Also, regarding the tank you need....
the owners manual probably states what size you will need but, with most heater like the one you have it will require a 100 lb tank (approximately 25 gallons). You will also need an inline regulator set to 11" to 14" of water column between the tank and the heater.

Not enough information to solve the problem correctly but I'll take a guess at it......

This heater requires a 100lb propane tank (approx. 25gal) with 1/2" or larger piping to deliver the correct volume of gas to the heater. If you are using a smaller tank (like a 10gal) or the piping is not the correct size you will not get enough gas to the heater to light the pilot. Also you should have a regulator set at 11" to 14" of water column installed between the tank and the heater. If the tank is connected directly to the heater you may have damaged the internal regulator in the heater.

a standard propane regulator should work. check on the required pressure for the unit and get a compatible regulator. try grainger supply. thermostat connections are usually 24 volt two wire, opens on temperature rise. connections on the burner relay are indicated TH-TH.