Boiler cycling on /off every 2 mins when heating

[Mmcgar]

Hi all
I'm afraid I'm having to post again about my boiler.
I noticed this morning that when it is heating the house it is only ON for around 2 mins, it then cuts out for another 2 mins before starting the cycle again. This does not seem right to me, I'd assume it would be on for longer periods (note that the thermostat has not reached temperature so nothing to do with that).
I just had the system balanced 2 weeks ago so my assumption is that this may not have been done correctly and 1 of the rads near the boiler is letting a high flow rate through which means the water is returning very hot to the boiler making it think it has reached temperature and causing it to temporarily stop? Does this seem reasonable? I only have a very basic knowledge of central heating systems.
It is entirely possible that the boiler has been doing this for ages and I'm only noticing it now that I have the heating on in the morning when the house is silent.
Either way I'm guessing this is not optimal and indication an issue with the system? Any tips on where to start? I will have a look at the lock shields on the rads near the boiler tonight and maybe turn them down a touch if required but other than that I'm at a loss.
If it helps, I have a 17 year old baxi standard boiler (which I'm praying lasts me through the winter!) and separate hot water cylinder. The system is piped microbore.

Thanks for any help

 

[AGAS]

I have a 17 year old baxi standard boiler

what baxi boiler - what model ?

 

[Mmcgar]

Hi I think it is from the baxi solo range la solo 2 or 3 maybe) I will check tonight after work though and confirm

Thank you

 

[Agile]

They are somewhat different so would be good to state exactly which one! Try to find the power of yours.

You need to measure or guess the flow and return temps on the pipes to/from the boiler. There should be a difference of about 11 C between them!

What pump make/model? What speed setting is it on?

Tony

 

[Terrywookfit]

The boiler is producing heat faster than the system is dissipating it. When the boiler reaches temp it turns off.

 

[Mmcgar]

Agile, see photo for pump, hopefully you can see the relevant info, it's just a picture I happen to already have so I can take a better one later if required
,
Thanks

 

[Mmcgar]

Hi Terry
What does this mean in practice, when the boiler starts cycling I should turn it off for a while until it cools down?
Is there any other way round this, while I'm at work my wife is home with our child, to be honest I wouldn't trust her to do this! And also I do need the house to heat up.
In terms of the system being recently balanced, the rads in our living room are VERY slow to heat up (I think the return pipe is a little blocked uplaontje plumber turned down the lock shield valves on the other rads to force the water to go towards the living room. Is it possible that this has led to a restricted flow on the system and I would therefore be better to open up the lock shield valves on the other rads?
I understand that it's only guesswork on a forum like this but would that seem like a reasonable plan?

Cheers

 

[Terrywookfit]

Why would you turn it off ? It is working as designed !! Heats up......Turns off....cools down.....Turns on !!

Solution would be a new boiler that modulates the flame .........But the payback would never happen.
Your existing boiler could outlast 2 new ones.

Are the rad valves twin entry ??

 

[Mmcgar]

Hi, no they are not twin entry

 

[Mmcgar]

The boiler is a baxi solo 2 PF.
I have just came in from work, I turned the heater nearest the boiler off and turned the heating on. The boiler ran for around 15 mins then cut off for about a minute. It is now cycling on and off every couple of minutes just as it done previously.

 

[Mmcgar]

Also I cant measure the exact temperature but the return pipe is roasting, also the front casing of the boiler itself is very hot

 

[Hugh Jaleak]

What temperature are the radiators? Do they take ages to heat up, if at all?

 

[Mmcgar]

The heaters do heat up, most of them in a reasonable amount of time. The 2 in the living room do take absolutely ages though maybe 30-45mins

 

[Mmcgar]

The rad in my upstairs hall (only about 1 or 2 metres from the boiler) does feel noticeably hotter than the rest though. I have turned it off to see if it makes any difference.

I had the boiler switched off for a while there while I bled the radiators. I have just turned it back in and it lasted around 6 mins before shutting down and beginning to cycle again

 

[Terrywookfit]

If it did not cycle, the rads would be cold.
What is your perceived problem.... what are you trying to achieve ??