Hot water cutting out/over heating?

[mallerton]

Hi,
I have a Potterton FF75 conventional boiler with a Megaflow Hot water cylinder, expansion tank etc...I have a problem with the Hot water not coming on at the set programmer times, it will run with a manual override or reset on the programmer but not as regular as it should. I thought initially it might be the programmer so have replaced that (was reasonable price and a direct Honeywell replacement). That seemed to fix the problem with the water coming on at the right times in day and eve but this morning no hot water...Im now thinking it might be the stat in the boiler itself?? If the water is getting to hot would it trip the boiler? I have checked pressure in expansion tank and all is well there...Please does anyone have any ideas what it might be and if its something like the stat is this something i could do?

Thanks in anticipation
Mat

 

[diamondgas]

mallerton does your boiler light up and work okay when you call for heating? Regards tripping the boiler, you'd know about it as there'd be flashing/red lights or pilot out (sorry, off your description of the boiler doesn't help me identify the model). There may be an issue with the Magaflow's associated components, stat or zone valve. Deffo not for you to mess with unless you're competent with diagnosing electrical faults!

 

[mallerton]

mallerton does your boiler light up and work okay when you call for heating? Regards tripping the boiler, you'd know about it as there'd be flashing/red lights or pilot out (sorry, off your description of the boiler doesn't help me identify the model). There may be an issue with the Magaflow's associated components, stat or zone valve. Deffo not for you to mess with unless you're competent with diagnosing electrical faults!

Hi, Thanks for the reply, the boiler works fine with the heating, the boiler has no (obvious) lights and the pilot light only comes on when initially called (or prompted by me). I probably wont touch it myself but wanted an idea on where to point an engineer. Dont want to be in a scenario where suggestions are made (wrongly) and parts ordered at my expense time wise

 

[diamondgas]

If th boiler's lighting up and the heating is fine then the problem lies beyond the boiler I'd say. If you've changed the programmer then it sounds like a problem around the megaflo. I'm assuming the hot water temp is down throughout the house yeh? all taps the same temperature?

 

[mallerton]

When you say HW temp down do you mean not as hot as usual? if so, then no, the water is hot prob hotter than normal with all taps the same temp.

 

[diamondgas]

When you say HW temp down do you mean not as hot as usual? if so, then no, the water is hot prob hotter than normal with all taps the same temp.

Okay mallerton can we back-track just a bit please. In your first post you said that you had "no hot water" this morning yeh? Other times the water seems too hot and it isn't always coming on as programmed! So when it is on it's working fine by sounds of it but you're never to sure as to whether it'll be on or not when the programmer calls for it to come on yeh?

 

[mallerton]

Yes you are right in your summation, sorry if the original post wasnt clear, the "no hot water this morning" just meant that the programmer appeared to be doing its thing but the boiler had not fired. Once its on (manually triggered by on/off of the programmer or the heating firing it) then it seems to be working fine.
Mat

 

[Kimou]

*deleted

 

[diamondgas]

Yes you are right in your summation, sorry if the original post wasnt clear, the "no hot water this morning" just meant that the programmer appeared to be doing its thing but the boiler had not fired. Once its on (manually triggered by on/off of the programmer or the heating firing it) then it seems to be working fine.
Mat

Okay Mat, well deffo need someone to have a look at your boiler. It sounds like it could be 'sticking' somewhere in it's lighting up stage either at fan proving or on older model Potterton's they'd falter at igniting the pilot and go no further only to light once the power was interupted!

Do you know the actual model potterton? is it a Profile or Prima?

 

[mallerton]

Not sure what make it is exactly but a google search showed up this [h=2]Potterton FF75 Boiler[/h] Boiler Model:FF75
Brand: Potterton
Manufacturer: Baxi Potterton
Boiler Type: Regular
SEDBUK Efficiency Rating: D
Seasonal Efficiency: 78.40%
Fuel Type: Gas
First Manufactured: 2002
Last Manufactured: 2005
Mounting Position: Wall
Condensing: Non-Condensing
Flue Type: Room Sealed
Fan Type: Fan
Average Power Usage: 23.45 KW/h
Maximum Power Usage: 23.45 KW/h
Electric Power Firing: 0 Watts
Water Storage Volume: 0 Litres
Insulation Thickness: 0 mm

Also an update is that the boiler wont fire for the hot water at all now i have to have the heating set to come on to fire it and keep it going.

 

[mallerton]

Not sure what the model is but a google search showed up this:

Potterton FF75 Boiler Boiler Model:FF75
Brand: Potterton
Manufacturer: Baxi Potterton
Boiler Type: Regular
SEDBUK Efficiency Rating: D
Seasonal Efficiency: 78.40%
Fuel Type: Gas
First Manufactured: 2002
Last Manufactured: 2005
Mounting Position: Wall
Condensing: Non-Condensing
Flue Type: Room Sealed
Fan Type: Fan
Average Power Usage: 23.45 KW/h
Maximum Power Usage: 23.45 KW/h
Electric Power Firing: 0 Watts
Water Storage Volume: 0 Litres
Insulation Thickness: 0 mm
Also an update: the boiler wont fire at all now for the Hot Water in order to heat it I have to set the heating to come on for an hour or so!
Mat

 

[diamondgas]

Found ya boiler, it's the same as a Profile. It sounds like external controls once again! You really need to get someone to have a look at it. The boiler is prone to PCB issues that can give intermittent lighting also! You tend to hear the boiler whir then off then whir then off then it'll ignite! GSR engineer matey!

 

[SafeGasInstall]

i dont think is to do with boiler more likely to be controls or other mechanical issue there ! your engineer will be able to EASY to fault fined it ! if you wish list your location to get some one from here to visit you on monday

 

[stevetheplumber]

i would be looking at the motorised valve on the megaflow

 

[mallerton]

Thanks very much for all your help guys I will get somone out to take a look