Baxi 133 HE Plus Serious problem Please HELP !!!

14 Dec 2006
Reaction score
United Kingdom
Hi i have a 2 year old baxi 133 HE plus boiler, when fitted i had the pipes power flushed.
The boiler has been great until now. The Hot water works fine but the central heating will not work. so i called the Heatteam who are part of baxi. they changed the PCB, Diverter valve & head, the Heater exchange, The vessel, and the ignition & the flow switch.
They could not get it to work and said they would send out a senior engineer but would be in 10 days time.

Anyway all of a suden the heating started working fine and has done for a week or so. then yesterday the rads were only getting warmish not hot as they should. and now today when the central heating comes on the boiler fires up for around 10 seconds then does nothing. you can hear the pump running.

so could anyone give me any help, the hot water works fine and pressure is normall.

i have noticed that the boiler did get quite hot and the pipes by the boiler got reall hot when the central heating was working. but like i said now the boiler will only fire up then nothing.

Please Please help
Sponsored Links
It sounds like a pump from what you describe in my opinion; almost like the impellor has come adrift... Although with the amount of work that has taken place on it; I would not like to really suggest anything without seeing it.
BUt i can hear the pump working and the hot water works fine
andy1234 said:
BUt i can hear the pump working and the hot water works fine

You may hear mechanical noises suggesting the pump motor shaft is turning.

How can you "hear" that the impeller is attached and also turning?

Sponsored Links
What does the pump actually do ? if it was the pump wouldnt the hot water not work at all ?
and why does the boiler fire up for a few seconds then stops but you can hear the pump running
Don`t know what your fault is but ignore pump comments as your boiler is a combi and if the pump was broke you would not get any hot water
Of course thats quite correct, I was only making the point that just because a pump makes a noise it does not mean that its pumping.

The obvious assumption is that all the changed parts are working. I am not able to make that assumption because there is clearly still a fault.

The obvious suspects are the diverter valve, its control circuit and the CH specific temperature sensors.

If Heateam staff engineers have changed all those parts and its still not working then its clearly not such an easy fault to identify or they may have made some error when changing them.

I dont think its likely than a non technical owner is going to be able to describe symptoms and get a diagnosis over the internet when Heateam have failed on site.

Either they have made a silly error or its a more involved problem.

Press Heateam to send a senior engineer sooner.

Ive tried and they can not get any one here until 10 days time. the heat team guy that called out first just changed parts think thats all his job is.

dont understand as when the hot water is on the boiler fires up fine, but with the central heating it fires up then cuts out after 10 secs. this is strange ?

any other advice ?
andy1234 said:
dont understand as when the hot water is on the boiler fires up fine, but with the central heating it fires up then cuts out after 10 secs. this is strange ?

It may be strange to you but thats how boilers work, or dont in your case!

Parts changing is a good way for less skilled people to get boilers working quickly when they have all the parts in the van and nobody is counting the cost of the parts used.

It does not work for smaller firms where we have to sort the boiler out on one visit and only charge the client for the one faulty part. We have to know how to diagnose what the real fault is.

Tony Glazier
Ok; my bad... I read the first statement wrong and thought it was now all off :(

So; when you turn the heating on... The pump starts; then the fan kicks in and you get some flames... Then it switches off shortly after?

When you turn on the tap; you get hot water fine; same temps as before and all works normal...

This may be a long shot; but I'm pretty sure there is a filter in the return of the appliance that can get blocked; drain out the boiler; remove the return connection and pull the filter out and give it a clean...

Depending on lots of factors; you still might have had some junk floating around your system which could cause it to block up.

Alternatively - I did have a similar appliance where the valves had been installed on the wrong sides; the filter was installed on the flow; as it got crudded up; it stopped the heating flow from escaping the appliance.

Just a long shot; but worth it if you've got a few hours and cannot get someone out.
In a normal installation, I would agree thats the most likely cause.

However, Heateam also know that as well and it would usually be the first thing they check before starting major part changing.

But in this one case perhaps it really was a most incompetent and inexperienced fellow who did not bother to telephone for technical advice and ignored the most common causes and just changed all the likely parts.

Unlikely one hopes, but anything is possible!

10 days is a long time to wait. In your position, if I were unable to check the filter myself I might be inclined to get a local plumber to come cheaply specifically just to clean the filter for me. 20 minute job so about £30-£40 and does not need a CORGI.

If I found it blocked then I would want a full refund from Heateam on account of total incompetence and unreasonable delay to have an expert attend.

Best of luck but let us know the outcome.

This boiler has a pump proving switch so there must be flow for it to fire up.
I think it might still be a problem with the d/valve or power to it
Likewise if the divertor was moving but the central heating had some form of blockage then the flow switch would not make. :idea:
Yes there is... Direct from the operation chart:

BAXI 133HE Manual said:
Pump On: The diverter valve and pump are on while the fan, spark generator and gas valve are off. After 10 seconds if the flow switch has made then Fan Pre-Purge occurs. After 10 seconds if the flow switch has not made then Anti-cycle occurs.

Even with the smallest amount of flow; the appliance "could" still fire for a short period. Like I said - It was a long-shot; but it's worth it if the heateam guy had neglected it. My thinking is along the lines that maybe there is enough flow to lift the paddle; but just not enough flow for the appliance to dump its heat.
yeah when heat team first called out he checked the filter and changed it.
could it be that i need the pipes power flushed but this was only done 2 years ago ?

the diverter valve & head where changed, when all the parts were changed it worked well for a week. but now the same problem as it fires up then cuts straight back off after 10 secs or so.

but hot water is working great.

i can only think there is a blockage of some sort, or the diverter valve again ?

DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.

Are you a trade or supplier? You can create your listing free at DIYnot Local

Sponsored Links