what is boiler cycling?

[petesurrey]

Hi,

I have an ongoing problem with my Grandee Oil Burner Boiler. It runs for 15 mins on initial start up, then stops running for 5 mins and then starts for 1 min, this continues until the programme timer turns it of.

This has a knock on effect onto how quickly it will heat our house (not very quickly!)

Heating World (makers) now say that it is a system problem and the boiler is "cycling" what ever that is?

My heating engineer says the problem is with the boiler?

Please help!

Thanks in advance, Pete

 

[doitall]

Its when the mother in law goes for a ride on her bike

 

[doitall]

Its when the boiler keeps shunting on and off.

The usual problem will be lack of circulation, pump not working to well or undersized, pipes undersized, motorized valve sticky, no by-pass or not adjusted, thermostatic valves on all the rads, boiler scaled up, room or boiler stat breaking down.

Circulation is where you need to look, age of the system would give some pointers, is it a new or old problem

And right at the bottom, when it was serviced last, the engineer could have fitted the wrong size nozzel

 

[petesurrey]

Well here goes:
The boiler is new and fitted Oct 07. This has had 3 new burners (due to lock out problems) last one only fitted 6 weeks ago.
The pump is new, but has been changed twice (due to failure).
The 3 port divertor is new, but has been changed 3 times (due to failure). The hot water tank is new.
The room thremostat (digital) is new.
The programmer is new.
All of the rads have new TRV's. All were flushed and inhibited in oct 07.

The system worked fine with the old (27 yr old) LPG boiler, onto the existing rads. The only work to the system was minimal, along the lines of removing the hot tank, changing some of the pipework to accomadate the new pump and 3 port divertor (this included the electrics). The pump has been replaced twice and more worrying the 3 port has failed 3 times, and the one that is on now (honeywell) only lasted 2 days?

Help!

 

[doitall]

All the parts you mention are very reliable, therefore the problem has to be with the system and the way its all been connected.

Lockout and indeed most if not all the symptoms are circulation problems.

I suppose the first question would be, was the changeover done by an Oftec guy and the boiler set up and installed as per the manufacturers guidelines.

What size pipes have been used from the boiler, what size pump, the type of system, e.g. one or two pipe, what attitude is the pump in, and is it on the flow or return, is it an open vented or sealed system

 

[petesurrey]

Hi, Many thanks for the response.

All of the questions you have asked are all beyond my capabilities, thats why I paid an OFTEC registered engineer to carry out all of the installation work.

I wish I could answer them in some more depth, but hey I am only a mere mortal.

Guess my engineer will have some explaining to do when the boiler makers do a site visit next week.

Pete

 

[doitall]

It will be interesting to hear what they have to say.