Paloma help

[BoaterJayne]

We have a paloma PH-5LFE which has started going out when you switch the hot water on. The pilot light is fine and the burner ignites when you turn the hot water tap on but after a short time the whole thing goes out. Any advice or suggestions gratefully received. If anyone knows someone who fixes these things please let me know. Thanks 

[David Mack]

Calling @Paloma Bob...

[Tony Brooks]

Certainly talk to Paloma Bob, but I wonder if this is some kind of blockage in the Paloma pipe work. Check to see if it has an isolation valve in the Paloma specific pipework that has been partially turned off, the pipe has been kinked/crushed, or we could be back to the treacle like gunge that can collect in gas pipes on older boats.

 

My thinking: if the pilot light works as it should then it is getting gas and presumably the flame failure (assuming your model has one) is holding the gas valve open, but as soon as you start to draw high volumes of gas both the burner and pilot light go out.

 

This assumes all the other gas appliances work as they should. If not then it might be a gas regulator problem (old age).

 

Has it got an extra bit of kit in the pipework near the gas bottles, if so it may be what is colloquially known as a gas fuse that "blows" (shuts off) erroneously when the Paloma demands a high gas volume.

Edited April 28 by Tony Brooks

[MtB]

1 hour ago, BoaterJayne said:

We have a paloma PH-5LFE which has started going out when you switch the hot water on. The pilot light is fine and the burner ignites when you turn the hot water tap on but after a short time the whole thing goes out. Any advice or suggestions gratefully received. If anyone knows someone who fixes these things please let me know. Thanks 

 

Sounds to me as though its overheating and the overheat thermostat is extinguishing the pilot and main burner together. There is a temperature control knob on the front of the Paloma IIRC. Does it still do it if you turn this down to a lower setting? 

 

Does the water come out of the hot tap as fast as it ever did, and just as hot, prior to it shutting off? 

 

 

 

 

[Tony Brooks]

31 minutes ago, MtB said:

 

Sounds to me as though its overheating and the overheat thermostat is extinguishing the pilot and main burner together. There is a temperature control knob on the front of the Paloma IIRC. Does it still do it if you turn this down to a lower setting? 

 

Does the water come out of the hot tap as fast as it ever did, and just as hot, prior to it shutting off? 

 

 

 

 

 

Yes, that makes sense, sounds a good call to me.

[MtB]

3 hours ago, Tony Brooks said:

 

Yes, that makes sense, sounds a good call to me.

 

My gut feeling is the heat exchanger is scaling up, leading to the outside of the water tube getting significantly hotter than water inside it due to the insulating effect of the layer of scale on the inside face. The overheat stat will probably be attached to a plate or pocket brazed to the outside of the tube, and it probably disconnects the thermocouple circuit when it trips, thereby turning off the gas. 

 

I predict the boiler won't re-light immediately after shutting down, but will after a minute or so once the overheat stat has cooled a bit nd reset itself. 

 

 

 

 

[Peugeot 106]

Paloma  Bob  bob07932 [at]aol.com 07932 [eight]15207 For spares, advice and exchange refurbished heater all at a very reasonable price
 

I got exchange refurbished one around £200 brilliant service if you need it

[Ex Brummie]

Not a Paloma, but similar on a Morco. I needed a new thermocouple/overheat stat and a new pilot. The best I could see was about £120.00 for parts with a five day delivery. Opted for the Ferroli that Morco were using as a replacement for their recall. Delivered next day for £200, including all connection fittings. Fitting was virtually direct, and with electronic ignition I'm not burning a continuous pilot,; a big plus with the cost of gas now.

[MtB]

21 minutes ago, Ex Brummie said:

Not a Paloma, but similar on a Morco. I needed a new thermocouple/overheat stat and a new pilot. The best I could see was about £120.00 for parts with a five day delivery. Opted for the Ferroli that Morco were using as a replacement for their recall. Delivered next day for £200, including all connection fittings. Fitting was virtually direct, and with electronic ignition I'm not burning a continuous pilot,; a big plus with the cost of gas now.

 

A Ferroli water heater that is a straight swap with a Morco is going to be nothing LIKE a straight swap for a Paloma! 

 

Just sayin'...

 

 

 

[Peugeot 106]

When I got mine from Paloma Bob @MtB was very helpful in ensuring I got the gas connection correct and gas tight. Saved me a fortune!

[BoaterJayne]

Thanks - that’s given me lots to try. Yes - I think it is getting too hot and shutting down. It does take a while to relight after the shut off and it takes less time to cut out again after. Thanks for the help.

[MtB]

28 minutes ago, BoaterJayne said:

Thanks - that’s given me lots to try. Yes - I think it is getting too hot and shutting down. It does take a while to relight after the shut off and it takes less time to cut out again after. Thanks for the help.

 

Ok this supports the overheating hypothesis. The heat exchanger 'probably' needs descaling.

 

 

[Tony Brooks]

29 minutes ago, BoaterJayne said:

Thanks - that’s given me lots to try. Yes - I think it is getting too hot and shutting down. It does take a while to relight after the shut off and it takes less time to cut out again after. Thanks for the help.

 

FWIW, I seem to recall taking the heat exchanger out of instant gas water heaters so we could fill them with kettle descaler. In this case we only undid a pair of water unions.

[Russ T]

19 minutes ago, Tony Brooks said:

 

FWIW, I seem to recall taking the heat exchanger out of instant gas water heaters so we could fill them with kettle descaler. In this case we only undid a pair of water unions.

I wish I'd known this a few years ago. I removed our paloma altogether, turned it upside down and filled it with kettle descaler.

 

I also recall there was a tiny strainer inside the cold water inlet that was totally blocked, which probably didn't help.

Edited May 4 by Russ T

[Tony Brooks]

I seem to recall that once the two unions on the gas diaphragm assembly were undone and very gently eased apart the whole assembly just lifted off lugs at the back or the heat exchanger, but we had a variety of different models, and it was over 50 years ago.