Potterton Prima f60 needs reset every 2 or so weeks

[scoobydo123]

Guys,

My Prima F keeps tripping. Have recently flushed the system (due to a different problem that is fixed and just thought it would do it good) X800 just on circulation and heating for 6 days then a couple of days of water which came out quite clear. Followed by X400 (will drop in the next couple of days). Circulation seems good all radiators getting hot within 20 minutes. No undue noises crash bangs or wallops. Any ideas what it could be, could a bit of sludge got wedged somewhere hopefully to come out when I flush and add x100.

Cheers

 

[Agile]

Do you mean a trip of the over heat stat?

For a start try turning down the control knob!

I would sugest you measure the flow temperature from the boiler.

You seem to be adding a lot of chemicals without an understanding of what they are used for or what you think that you are trying to deal with.

X800 is just a high speed version of X400 ! Its main purpose is to encourage deposits into suspension!

Tony

 

[scoobydo123]

Tony,

Yes the overheat trip is what is cutting in. Have graudually been turning the stat down. Haven't got the equipment to measure the flow temperature so will go with your suggestion and see how it goes. Obviously if I have to turn down too far then I will have to get someone out to diagnose the problem. Can you get a fault with the trip hence your advice to test the flow to see if it comes in too early?

Sorry didnt realise the difference from x800 and x400 but know now.

Cheers for your help

 

[Agile]

Those boilers had a temperature control knob which almost overlapped with the operating temperature of the overheat stat. Add a missing pump over run or bypass and there is a built in tripping mechanism.

Without being able to measure the temperature you have no way of know whats wrong at all.

Its more efficient to run the boiler at the lowest flow temperature that provides enough heating. Nothing wrong with changing it in milder or colder weather. Be careful as the knobs break off easily!

Tony

 

[scoobydo123]

LOL The whole thing seems to self destruct whenever you go near it. I am sure the panel on the bottom of it is made out of ice cream wafers.

Out of interest how would you go about measuring the flow temp. Is there a pick up point on the boiler or do you have to break into the flow pipe some how?

Thanks a lot (and boiler so far ok)

 

[Agile]

You use a contact thermocouple thermometer pressed onto the flow and return pipes

The differential should be around 11°C. Much higher than 15°C and there is a case of insufficient water flow rate.

So no invasive surgery is needed.

Tony

 

[scoobydo123]

Great I understand, is it no so much the actual temp but the differential that we are concerned with. Will see if I can borrow one. Did have something similiar for mapping ECU's on cars for measuring intercooler temps.

Thanks as always

 

[Kev F]

got one of these myself, check for any air in the system, sounde stupid but it snot, also when the pump is on its way out or blocked it will do this

 

[scoobydo123]

Well drained it out again and still quite murky. See the attached

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• scoobydo123
• 18 Jan 2009
• 1

. So it has had 2 lots of flushing chemical. Now running on water no x100 yet, wanted to see how it goes before putting that in.

 

[Agile]

That looks discoloured but without any particles.

Its an odd colour but your use of chemicals was odd!

Drain and refill a few times using the pump to circulate until its pretty much clear or light straw.

Then measure the temperatures before adding any X100.

Tony

 

[scoobydo123]

Tony will try to beg borrow or steal a contact thermocouple and report back.

Cheers again

 

[scoobydo123]

Tony sorry for the delay, 2 weeks waiting for my temp probe to arrive from ebay (Uk seller as well).

Anyway measured the flow at the pipe just before the pump and it is 59c and the return is 51c. So am I correct in saying that it appears I have good flow? PS it hasn't tripped since before my last post.

cheers

 

[Agile]

That is fine as a differential but a flow temp of only 59° is rather low at this time of year.

You should be able to turn up the temperature to about 70°C and still be well away from the over temp trip temperature if everything else is correct.

Tony

 

[scoobydo123]

Tony,

I am unable to crank the temperature up very much as it just trips again. To be honest I have always had it operating at just over 3 on the dial, if I go above 4 it seems to trip. Any ideas or just leave alone?

Thanks again

 

[scoobydo123]

Sorry to raise again but it appears like our old friend of nuisance trip is back. Since last time I have installed a boiler buddy and been running fine during the summer season. Fired her up for CH and cranked the temp up on the thermostat (on the boiler). This resulted in a nuisance trip followed by normality. Anyway today I finished work early and thought I would have a poke around with a magnet on the pipe work. The 15mm to the F&E had no magnetic attraction however the flow pipe was major attracted. The magnetic pickup was able to support itself for the vast majority of the pipework from the flow on the top of the boiler all the way almost to the pump. See the attached photos. Is this classic time to get the pipe cutter out and renew this section?

Thanks

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• scoobydo123
• 27 Sep 2010
• 1

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• scoobydo123
• 27 Sep 2010
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• scoobydo123
• 27 Sep 2010
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• scoobydo123
• 27 Sep 2010
• 1