Early Recycling

[Al Growler]

My Vaillant boiler has started to perform differently. It now starts to recycle early after a few minutes when flow temp is 40 or 50 degs. The recycling symbol flashes for 10-15 mins then the boiler fires up again until target flow temp achieved.

I called Vaillant out under warranty who fitted a new pcb and flow and return sensors. It went back to performing normally for a couple of weeks, but then started to recycle early again. My suspicions now have been diverted to a possible pump problem.

I noticed that a couple of rads near the boiler were not heating up to same temp as the rest so I turned the pump up from mid to highest setting. The cooler rads got hotter and the boiler stopped recycling early. The pump is quite noisy on highest setting and gets very hot so don't know whether to switch down again. Could the pump need a clean out or replacing.

Thanks in advance for comments and advice.

Cheers

Al

 

[Madrab]

If it still isn't right then time for Vaillant again. The more you play with it the harder it will be for the Vaillant guys to rectify.

 

[Al Growler]

OK, thanks for the feedback.

 

[Harry Bloomfield]

I noticed that a couple of rads near the boiler were not heating up to same temp as the rest so I turned the pump up from mid to highest setting. The cooler rads got hotter and the boiler stopped recycling early. The pump is quite noisy on highest setting and gets very hot so don't know whether to switch down again. Could the pump need a clean out or replacing.

What ever the cause, the symptoms suggest a poor flow, or a restriction somewhere. Your boiler is not able to get rid of the heat it is able to generate, quick enough.

 

[Odds]

How often have you serviced the boiler?

 

[Al Growler]

Boiler coming up to 7 years old and warranty will expire in March. It has been serviced annually on the dot. It is currently working very efficiently with pump on highest setting, but concerned as noisy, very hot to the touch, and that it might seize up if clogged. Got my gas engineer coming out next week for my service. Will ask him to check pump. If I get Vaillant out again, and it's not the boiler, will get charged anyway.

 

[Odds]

Sounds obvious but you've checked to make sure the air vent isn't blocked?

 

[Al Growler]

Wouldn't know where to start to be honest. I need to keep releasing air out if my highest rad, and not sure if that points to anything.