My Potterton Profile 80e often doesn't start up

[combispecialist]

forgot 2 say ure bypass should be a gate valve with a red handle situated in airing cupboard tee'd off before flow into the motorised valve/valves

 

[NZH]

wot u need 2 do is get the boiler working by pressing the rest button,stand and waite while its running,is there any gurglying noises??if so it may be air in system causing boiler to overheat??does the flow pipe get red hot after being on for only 20-30 secs???if so this would suggest circulation or pump issue???if the system was really sludged up did the plumber replace ne pipework in airing cupboard i.e air sep or h section????if he didnt then that could be cause as flush wont completly unblock a badly restricted air sep.only other thing is if the flow pipe isnt red hot and the over heat is still tripping then its a faulty o-heat stat.hope this helps u

Combispecialist

Many thanks for this guidance.
Done as you directed.

The flow pipe does not get red hot after 20/30 seconds, quite warm after a few minutes. There is some ticking but not what I would describe as gurgling in the boiler.

I should have mentioned earlier perhaps that we used to have to bleed the rad in the bathroom (one nearest the pump and the immersion tank) every couple of weeks as it was cool at the top and hot at the bottom. Whereas the recent symptoms in some rads were coolspots at the bottom and hot at the top.

Plumber didn't replace any pipework.

Flow pipe is too hot to keep my hand on after about 7 or 8 minutes.

Boiler has tripped after about 18 minutes (should have checked the clock properly when I reset it

Flow pipe is too hot to keep my hand on, return is warm in comparison, boiler casing is hot as before.

 

[NZH]

forgot 2 say ure bypass should be a gate valve with a red handle situated in airing cupboard tee'd off before flow into the motorised valve/valves

Just seen you note aout bypass valve - we don't have one of these........... although there are pipes in the immersion cupboard going to the loft with valves in them, but I always thorught these were the flows to the header tank and the cold water tank

 

[seco services]

you might not have a bypass or pump overrun. mines not got a pump overrun.

 

[Agile]

You need to feel the TWO pipes from the boiler while its heating up.

If the pump is OK and the system not blocked then there will only be a skight difference of about 10° between the two pipes.

If the cool one is still almost cold then there is a serious flow/blockage problem.

I really cannot understand how anyone can come and powerflush without including dealing with any other flow problems on your system.

Tony

 

[NZH]

You need to feel the TWO pipes from the boiler while its heating up.

If the pump is OK and the system not blocked then there will only be a skight difference of about 10° between the two pipes.

If the cool one is still almost cold then there is a serious flow/blockage problem.

I really cannot understand how anyone can come and powerflush without including dealing with any other flow problems on your system.

Tony

Agile/Tony

Thanks for your reply, I think the difference in temp is greater thatn 10 degrees, but difficult for me to check without having thermometers to clip on to both pipes.

I was about to post another note to say that it's just over an hour since the boiler last ran, and I'm about to press the reset button.

I was going to ask a further question of combispecialist about his diagnosis of a "faulty o-heat stat" and to ask - I can understand that it would (should) detect when the temp is too hot, but I can't understand why it doesn't detect that the temp has dropped below the one set on the hall rad, and then restarted the boiler?

Although looking at what I've just written, maybe that's part of the reason that combispecialist reckons it's a faulty 0-heat stat?

Thanks - Neil

 

[NZH]

I reset the boiler at 1935hrs, it ran until 1957, and clicked off, so for 22 minutes, during the last three or so minuites of running I heard what I can best describe as trickling water sounds within the boiler, rather than gurlgling.

The flow pipe is too hot to touch for more than a couple of seconds, the return is hot but I can hold my hand on it for about six seconds.

Hope this final bit of information is able to get a final conclusive conclusion from combispecialst, Agile or seco services...

I really appreciate your help guys..

 

[NZH]

I reset the boiler at 2006, it stopped at 2018, and now at 2020 hrs it's started up again, just like one might expect it to(?) if it were operating normally.

 

[Agile]

If you hear water sounds it seems its not filling properly.

Have you checked the F&E tank and run water off to see if the level falls? See FAQ.

Tony

 

[combispecialist]

the question regarding o-heat stat........its a manual resetable stat,these do not automatly "make" when the system cools,u physically have to reset it.its just a type of stat.if its a blockage in the system normally the boiler would bang and clatter within 20-30 secs,if its not doing that i would probably think theres no blockages but its sounding like a job u really need to be there to diagnose fault,when the o-heat trips if its working ok and doing its job correctly then the flow pipe would be that hot that u could barely touch it.....i.e 90 degrees

 

[NZH]

If you hear water sounds it seems its not filling properly.

Have you checked the F&E tank and run water off to see if the level falls? See FAQ.

Tony

Tony
I'll ask our plumber if he did that on Friday.

Still like to hear from combispecialist if he thinks it's still the overheat thermostat.

Regards - Neil

 

[combispecialist]

forgot to ask,u said it o-heated after 18 mins????do all of ure rads get at least warm at this stage????if they are all getting warm then it cant be a circulation issue,do u find downstair rads poor??

 

[combispecialist]

after fully reading ure last reply i would say its either blocked cold feed,circulation issue pump etc,if u can hear trickling around boiler its when the system is not completely full,as previously mentioned it could be something as easy as a stuck ball valve in ure header tank.another simple check would be to see if u have a gate valve on ure cold feed pipe to the central heating system.........make sure its fully open....anti-clockwise

 

[NZH]

forgot to ask,u said it o-heated after 18 mins????do all of ure rads get at least warm at this stage????if they are all getting warm then it cant be a circulation issue,do u find downstair rads poor??

No, downstaris rads are all fine; kitchen, dining, lounge x 2, study, cloakroom. Only ones that are a little cooler are bathroom (next to immersion and pump) and shower room (vertical towel rail) which I guess is the next one in line, and I think the plumber turned down the lockshield valves on these two, a little more than they were before he came to do the flushing.

Thanks - Neil

 

[NZH]

Should have mentioned that since the boiler started itself at 2020hrs, it has lit, stopped and lit isself again about 3 times since then. Time is now 2105 by my watch ( a bit ahead of PC clock). this is how it was behaving (normally) on Weds or Thursday last week after malfunctioning for the previous two weeks and yesterday adn today until this evening..............