Potterton Profile 100e Boiler

[gillpeer]

I have a Potterton Profile 100e boiler. Even when the programmer is not switched on, the boiler seems to come on every few minutes for a few seconds and then switches off. At the same time, the pump is hot all the time and makes a noise as if it is all the time.

I have a megaflo system and a Randall 922 electronic programmer.

Could it be that when the megaflo system was installed, the wiring was not properly, so that whilst the timer is showing it is off, it is still on thereby the pump remaining on all the time and the boiler switching on till it reaches the temperature set on the thermostat in the boiler.

I called one plumber who said that it is normal for the boiler to fire every few minutes because of the megaflo system.

Any views would be appreciated.

 

[Agile]

I called one plumber who said that it is normal for the boiler to fire every few minutes because of the megaflo system.

Any views would be appreciated.

It is normal, but only while its still heating the hot water cylinder.

It is not normal when HW is deselected on the programmer.

A boiler engineer would have been better able to evaluate the problem.

Has this only just started happening or has it always been like this?

Tony

 

[mickyg]

its not normal....I would hope the wiring is correct for the megaflo as its safety critical. It could be a stuck microswitch in one of the motorised valves, this would normally be the cause of such a fault. Is it a new problem or has it been like this since the megaflo was installed?

EDIT: damn that mr glazier and his speedy replies

 

[bengasman]

With the timer off, the boiler should never fire, simple as that.
Motorised valve is first suspect as mentioned above, or failing timer. In case you are planning on diy, bear in mind that it is 230V and as there is something not working properly, the power can come on at any odd time without warning unless it switched off at the spur.

 

[glasgowgas]

it might be something more simple but i had a similar problem
in my brothers new build home about 6 weeks ago

170 litre megaflow cl (the pre plumbed version)
vokera mynute 20 he

he had same scenario, boiler firing outside htg and hot water demand

the answer was the boiler external control link had not been removed,
but megaflow 2 x 2 port valves were wired back to programmer,

so boiler ticking over in effect 24 hrs a day. as soon as a demand for ch activated thru prog, ch 2 port valve opened and the boiler flow and return had somewhere to go, same for hot water, same for htg and hot water

it was easily rectified but the 2 scenarios sound similar to me.

best of luck to the OP

 

[twgas]

With the timer off, the boiler should never fire, simple as that.

unless there's a frost stat.

Motorised valve is first suspect as mentioned above, or failing timer. In case you are planning on diy, bear in mind that it is 230V and as there is something not working properly, the power can come on at any odd time without warning unless it switched off at the spur.

I agree

 

[bengasman]

With the timer off, the boiler should never fire, simple as that.

unless there's a frost stat.

Come on, I know the summer hasn't been great, but you are exaggerating.

 

[gillpeer]

Glasgowgas:

it was easily rectified but the 2 scenarios sound similar to me.

How was it rectified, please?

twgas:

What do you mean by "unless there's a frost stat."

Thanks for the quick responses.

 

[twgas]

With the timer off, the boiler should never fire, simple as that.

unless there's a frost stat.

Come on, I know the summer hasn't been great, but you are exaggerating.

Could be the fault (well it is possible)

 

[glasgowgas]

Glasgowgas:

it was easily rectified but the 2 scenarios sound similar to me.

How was it rectified, please?

if you have wiring diagrams for your boiler, you should be able to see if the external controls link HAS been removed.

just a suggestion, does my described situation sound like yours?

 

[gillpeer]

Reply to Agile:

The boiler is about 20 years old.

I had the megaflo installed about 2 years ago and had a new pump and valves at the same time. The timer and the room thermostat are old.

The problem I have has been there ever since I the megaflo installed. I have been too lazy to do anything about it as I am getting hot water and central heating is working fine but now I feel I must have this problem sorted out once and for all.

Can you tell me how you reply with message highlighted as an insert like the way you replied to my initial post.

Thanks

 

[gillpeer]

Glasgowgas:

it was easily rectified but the 2 scenarios sound similar to me.

How was it rectified, please?

if you have wiring diagrams for your boiler, you should be able to see if the external controls link HAS been removed.

just a suggestion, does my described situation sound like yours?

Exactly like your situation

 

[glasgowgas]

your a quick learner, took me 300 posts to use quotes!!!!!

now you have given more details, im convinced your boiler has not been
wired to the megaflow

if you feel competent to do so, look at megaflow wiring instructions they are quite well drawn out and easily followed

another poster on here a D-HAILSHAM is an absolute genius with wiring and controls wiring, maybe try giving him a PM

 

[gillpeer]

your a quick learner, took me 300 posts to use quotes!!!!!

now you have given more details, im convinced your boiler has not been
wired to the megaflow

if you feel competent to do so, look at megaflow wiring instructions they are quite well drawn out and easily followed

another poster on here a D-HAILSHAM is an absolute genius with wiring and controls wiring, maybe try giving him a PM

So is the wiring of the boiler incorrect or the megaflo wiring. As the boiler is heating up the water, it must be connected to the megalfo.

How do I get in touch with D-HAILSHAM? What is a PM? Sorry for my ignorance of the terms used.

 

[mickyg]

If its been like it since the megaflo was installed then its almost certainly been installed incorrectly. Is it not possible to contact the installer of the megaflo? Its a shame you didn't contact the installer earlier so he could rectify his mistake. Now you need to decide what to do...if you want assistance tracing the wiring then you will get plenty of help here, or if you don't feel confident you'll need to get someone in to solve it for you.
If you look up wiring diagrams for an S plan heating system you should get an idea of what should be going on, but just be aware that the electrical control of the megaflo is safety critical, and if in doubt call someone in.
mick