Flow switch on Ariston boiler

[loveaduck]

Sorry if you've read this before. I decided to repost because I didn't get any replies and, with all the expertise on this forum, I'm sure someone can help me. I hope.

I have an Ariston 20/1 MPS combi boiler - at least ten years old. A few weeks ago, it stopped firing consistently. Most of the time, it worked ok, but sometimes it wouldn't fire at all, especially if I wanted hot water while the central heating was on. A few days ago, it stopped firing altogether.

An engineer diagnosed a faulty flow switch (I've had this problem before and had a new flow switch put in previously, in March 2004). He bypassed the flow switch by connecting the blue and brown wires and the system worked fine. He told me, if it was his boiler, he would simply bypass it , but said he could not officially recommend this course of action.

Does this diagnosis sound correct? What are the risks (if any) of bypassing the flow switch in this way? Thanks for any replies.

 

[Agile]

You have not made it totally clear if this engineers action has just been done to restore boiler operation. If so why is he not replacing the failed part?

The system flow switch is a safety device to prevent dry firing. It should never be bypassed except on test by a competent person.

If it were bypassed and the pump had failed or there was no water pressure then the boiler would seriously overheat although there is an overheat stat which would eventually turn off the gas but permanent damage might already have been done.

Tony

 

[loveaduck]

Thanks, Tony. Sorry if I didn't make it clear. The engineer bypassed the flow switch just to test it. He put it back after. He has offered to replace the flow switch, but he said he couldn't see any risk to bypassing it on a more-or-less permanent basis (if I wanted to do this myself), because there was another safety system in case of the water pressure falling too far (the only situation he could think of where the lack of a flow switch would matter).

It sounds like you think there are other risks he wasn't taking into account. Am I right?

 

[HarrogateGas]

One must ask ones self, why is the flow switch there in the first place?? The manufactuers dont put them on for fun and therefore they should not be by passed......to do so is dangerous and also Riddor reportable. He is giving foul advise. i would get rid of him and find someone who is willing to do the job properly and safley....If damage was done to your property by the boiler would your insuers pay out when they find out you by passed a saftey device on you boiler (obvoiusly not knowing what you were doing and therefore breaching Gas installation and Use regs as you would certainly not be deemed competent?)