Rinnai REU-58E water boiler ignition issues

[Tabs Lee]

Hello

I installed a Rinnai REU-58E water heater and the pilot flame lights but main burner won't ignite. When the hot water tap is turned on the pilot flame goes out. Is this to do with water pressure or gas pressure or something need to be removed or adjusted on the install?
 

Thanks in advance!

[magnetman]

You probably need a gas safe person to check it. 

 

I had a Morco which is similar and one thing which happened was that the pilot flame jet would get blocked with dust which made the flame go smaller and yellow. The pressure of the gas coming onto it occasionally put the flame out. 

 

Is your pilot flame yellow? ETA I see it is blue so scrub the next bit! 

 

The solution I was given for this was to blow through the pilot flame outlet with a straw or a can of compressed air computer keyboard cleaner. It worked. 

 

This might not be what is wrong with yours and as I said you may need to have it looked at by someone qualified to tinker with gas appliances. 

Edited January 9, 2023 by magnetman

[MtB]

Sounds like an empty gas bottle to me! 

 

 

[rusty69]

I've got one of those that does exactly the same thing. Will be interested in the solution.

[MtB]

2 minutes ago, rusty69 said:

I've got one of those that does exactly the same thing. Will be interested in the solution.

 

First step in diagnosing it is a manometer on the appliance inlet gas pressure test point. See if the inlet pressure falls to zero when the tap is turned on, or stays at 37mb approx. 

 

 

[rusty69]

3 minutes ago, MtB said:

 

First step in diagnosing it is a manometer on the appliance inlet gas pressure test point. See if the inlet pressure falls to zero when the tap is turned on, or stays at 37mb approx. 

 

 

That's another job for the list then.

[MtB]

31 minutes ago, rusty69 said:

That's another job for the list then.

 

Yes, the list that gets progressively and slowly longer while the content on it constantly changes. That's what mine does anyway.

[Dav and Pen]

I installed one of these and seem to remember there were 2 heat settings. If yours is the same try it on the lower one and see if that gets it going. You have a good strong pilot light so gas should be ok and you can check you water pressure ours max was 2 bar and worked fine.

[MtB]

5 hours ago, Dav and Pen said:

You have a good strong pilot light so gas should be ok

 

And straight away the first rule in fault tracing is breached. Don't make assumptions. TEST and prove it!

 

The fact the pilot goes out when a tap is turned on is quite strong evidence the gas supply is NOT ok on many water heaters. 

 

 

[Paloma Bob]

First guess, not enough gas ! Main valve opens to feed burners, what little gas there is goes there rather than the pilot, hence the pilot goes out.

 

 

[Mike Hurley]

How old is the regulator on the bottle?

[MtB]

54 minutes ago, Paloma Bob said:

First guess, not enough gas ! Main valve opens to feed burners, what little gas there is goes there rather than the pilot, hence the pilot goes out.

 

 

 

Yes, my view exactly. 

 

But the OP seems to have gone AWOL, sadly. 

 

 

[Tracy D'arth]

Undersized or kinked gas pipe?

[MtB]

2 minutes ago, Tracy D'arth said:

Undersized or kinked gas pipe?

 

The whole situation is faintly odd. That water heater was discontinued a decade ago yet it looks like a brand new installation, never used. The gas pipe looks like 5/16" which would be big enough if the gas run was short. But even if long I don't think 5/16" is so small as to cause the gas pressure drop to the point where the pilot goes out. But yes a kinked pipe could do it.

 

My best guess is this is an old boat with a new water heater being installed. I'm wondering why the old one was replaced, a similar problem perhaps. If so, it is probably that oily gloop that accumulates in old propane gas pipes. Gas condensate.