Boiler cycling on /off every 2 mins when heating

[Mmcgar]

Hi Terry, basically I'm wondering if this is a sign of a problem, I didn't notice it doing this before. Basically now after about 15 mins of running the boiler just constantly switches on and off every minute or so, I assume this is not good for the boiler. It may be that I'm totally mistaken and I admit that my knowledge of central heating systems is poor but I am an engineer and can't help but suspect that this is a symptoms of a problem?

Would you not be concerned by this? I probably am a bit hyper sensitive to the boiler due to its age.

Thanks

 

[Terrywookfit]

You need to measure the boiler flow and return temperatures to see what is happening.

 

[Mmcgar]

Ok cheers, is there a particular way to do this? I. E. Something like pipe thermometers?
I can get something to do it tomorrow.

Thanks

 

[AGAS]

are ALL radiators on ( every single one )

 

[Mmcgar]

They were on. I tried turning off the rad in the bathroom (right next to boiler) in case water was just just circulating through it and back to the boiler. When I say turn off I turned it down to the frost symbol.
Tonight when I was checking the rads I did notice that the rad in my daughters room was cooler than the rest so again I have turned this down to the frost symbol to try and isolate it from the system in case it's causing issues.

As you can probably tell I'm guessing at things here!

 

[Hugh Jaleak]

I suspect you have a circulation issue, microbore doesn't help as can soon start to clog up if the system is dirty. Do you know if there is sufficient inhibitor in the system?

Turning off radiators that do work is contrary to what you should be doing, its the ones that aren't working you need to open up to try and force flow through them!

 

[Mmcgar]

Hi Hugh.
I just had the system drained about a fortnight ago, a cleanser was put in (only for around an hour thiosondont know how much good it will do), inhibitor was apparently then put in

 

[Hugh Jaleak]

Inhibitor will prevent any further corrosion inside the system, but wont undo any damage already done. When it was cleaned, what colour was the water coming out? Secondly, why was the system being worked on?

 

[Mmcgar]

I think there was some blackness to the water but not too bad I think.
I was having trouble with the radiators in my living room taking ages to heat up, so I got them blasted through with water to try and clear out any sludge. While doing this I had them put a cleanser through to see if it helped

 

[Hugh Jaleak]

It's not the rads that'll be the problem, microbore pipework by its nature is more prone to blocking up.

 

[Mmcgar]

Is there any good way of unblocking it? Is it worth putting the cleanser in for a week or so to break stuff down? Is this a diy job or best left to professionals?
On a side note is this likely to be causing problems /damage to the boiler? The heating is working so if it's not doing any harm I'd be happy to leave it for now

 

[Razor900]

Two pages and no one has asked the OP if there's a room thermostat fitted?

Guess what a room stat helps to prevent.............

 

[Terrywookfit]

Two pages and no one has asked the OP if there's a room thermostat fitted?

Guess what a room stat helps to prevent.............

Try reading the first post FFS............ (note that the thermostat has not reached temperature so nothing to do with that)..

 

[Mmcgar]

Yeah, hive 2 room thermostat fitted and as Terry said, it has not reached temperature (generally 20 degrees) when cycling starts

 

[AGAS]

if i was you , i would just get someone in to get more information to see if its your system or a boiler fault . you could be chasing your ass for something really stupid thats been missed , as your communicating through a computer and we are not there