Central heating/hot water issue

[dan77714]

Hi all
Just wondered if anyone would be able to offer some advice. I have a Baxi Combi 105he boiler and its recently been having a bit of a frustrating issue with it. It seems to be locking out with the 60 degree fault on pump/low pressure light flashing. The issue begins intermittently at first but then happens continuously. I've had an engineer out four times so far and they are able to fix the issue at the time but then it returns once they leave.

On the first visit they changed the PCB. The fault went for a bit but returned the next day.

On the second visit the fault seemed to disappear while the engineer was here, he couldn't find a fault but it returned when he left.

On the third visit the engineer said the pump was fine but there was air lock in the system. He drained the boiler and recharged the expansion vessel which made the fault go away... but of course it returned the next day.

Finally on the fourth visit, they replaced the pump. This also worked for a bit but the fault still returned once he had left.

I have worked out I am able to get the boiler to work for a little while in order to allow us to have a shower by completely draining the heating system out of the radiator drain valve and re-pressurising it, however the fault returns after a couple of hours mainly after the boiler being dormant.

I'm unfortunately not a gas safe/competent engineer so I appreciate this isn't something i'm going to be able to fix myself but is there anything I could suggest/insist the engineer checks on his next visit? I am at the end of my tether with this and kind of losing faith in them especially as I have to wait over a week between each visit for the next available appointment which is little frustrating as it is starting to get cold now.

Any suggestions would be much appreciated!

Thank you in advance!

 

[dan77714]

I should also mention the boiler pressure seems to also drop by itself over time but I haven't found any leaks in the central heating system or anything.

 

[Wannabebetter]

I should also mention the boiler pressure seems to also drop by itself over time but I haven't found any leaks in the central heating system or anything.

Check the safety discharge pipe outside, if no water present, then tie a bag around it and check again. Hopefully you’ll get a answer on the other, plenty of good engineers who know this boiler inside out.

 

[dan77714]

Thanks for the reply, i'll try that

 

[terryplumb]

You need to find a better engineer ,not much faith in the one your using. Swapping parts to find it hasn't resolved the issue means it wasnt diagnosed properly in the first place.

 

[dan77714]

Hi terryplumb, I definitely agree with you.
Unfortunately in this case i'm at the mercy of who the boiler cover people send out and when they decide to send them out. I have had different provider come out to have a look at it but I got the feeling they didn't really want to do touch it given another company had already been there. I'd rather not name this particular company here but let's just say, they should know better. I understand intermittent problems are the worst kind and most difficult to resolve. It's just the biggest frustration is the long lead time in between when they are able to visit. They came quickly for the first visit, however subsequent visits to rectify the ongoing problem have had a long wait without hot water.

I'm just trying to see if anyone has any suggestions as to what the problem might be so it can be sorted when the engineer next visits and I can avoid having to call them out again for a sixth time.

 

[jackthom]

Try to keep an eye on the pressure gauge when the boiler is running for a while to see if it increases towards the 3 bar mark. That would indicate a problem with the expansion vessel and you would then be likely to lose some water/pressure via the safety valve (PRV).

 

[ianmcd]

sounds like crap or faulty Diaphragm in the pump proving manifold, a very easy repair, and very common with that boiler

 

[dan77714]

Hi Ian.
Thank you so much for your reply, you were right on the money with that being the problem.

I had really hoped the engineer would come to that conclusion by himself when he saw the fault had returned again, however I had to show him your post after he went to his van and got yet another new pump out to fit . He then called someone else to check and they agreed with you.
All seems to be working perfectly now.

Thank you so much once again for your help, it's very much appreciated!

 

[ianmcd]

Hi Ian.
Thank you so much for your reply, you were right on the money with that being the problem.

I had really hoped the engineer would come to that conclusion by himself when he saw the fault had returned again, however I had to show him your post after he went to his van and got yet another new pump out to fit . He then called someone else to check and they agreed with you.
All seems to be working perfectly now.

Thank you so much once again for your help, it's very much appreciated!

Thanks for updating Dan, is always usefull for others, sadly too many never reply to say what the problem was

 

[terryplumb]

Another excellent remote diagnosis from ianmcd..well in Ian

 

[dan77714]

Hi Again, sorry to have to resurrect this thread. Just had a quick question, since the fault was repaired the hot water and heating is still working fine however I have noticed that the boiler has been making a sort of gurgling/spraying noise when using hot water or when the preheat comes on. The sound doesn't seem to occur for the heating but I have bled the radiators anyway and that didn't really make any difference. I've also checked the two pipes outside (the condensate and pressure relief pipes I think) and they don't seem to have any blockages that I can see.

The noises only seems to have started since the engineer completed the repair, could it have something to do with the fix or is it maybe a different issue? And is it something I need to worry about and get the engineer to come back and check?

Thanks in again in advance!