Baxi Bahama 100

[verbis]

Hi

the boiler has stopped giving hot water. The heating still works fine. No strange noises etc. On the actuator the white switch does not move when hot water is requested. If a hot tap is turned on, then the switch can be forced but the water only runs tepid.

Suggestions anyone please?

Mk

 

[Agile]

I dont reallt follow all that you are saying!

First the DHW flow switch has to operate, these sometimes stick!

Next the system flow switch has to operate, these can also stick.

The plate heat exchanger may be rather blocked, that can also have the effect of making the system flow switch reluctant to operate.

Tony

 

[mickyg]

If when you run a tap nothing happens then its probably your hw flow switch faulty, if you hear the pump run and then nothing then its probably the pump flow switch(both same type of switch). They are a pretty awful design unfortunately, i think they were modified at least once. On the bright side they are very easy to replace, and sometimes you can even remove and clean them and they will work again. In any case, for the sake of 30mins work, you can take them both out, give them a nice clean and pop them back. certainly worth a try.

 

[superdupergasman]

do the rads heat up if you left the tap running for a long time??

Its either a jammed divertor cartridge (very commom on these)
or the head of the valve is kapoot!

If nothing at all happens when you run a tap and the heating works perfectly then its the DHW flow switch thats your problem.

 

[baxpoti]

If nothing at all happens when you run a tap and the heating works perfectly then its the DHW flow switch thats your problem.

Correct answer

 

[verbis]

Thanks for the advice. I replaced the diverter cartridge at the weekend, before I checked the posts this morning. The problem still persisted but at least I now have a new cartridge in place?! Beginning to think I would rather have a new boiler in place

Is the DHW switch the small white switch I can see on the casing that I had to remove to access the cartridge? This is the switch I have referred to as having to push it forward until it clicks in.

 

[Agile]

The flow switch and the DHW switch are both the same type and have a knurled ring which has to be unscrewed to remove them.

They are both black plastic like all the rest of the water bits.

I cannot guess what you have been pushing, it worries me that it might be an overheat cut out stat!

Tony

 

[verbis]

Are these the same, or do they just look the same? Where is it on the boiler? Do you have an image by any chance in a million? I have spoken to a supplier and he cannot find a reference to a DHW switch but he can find the flow switch part.

 

[superdupergasman]

I cannot guess what you have been pushing, it worries me that it might be an overheat cut out stat!

Tony

Verbis has been pushing the lever on the side of the honeywell diverter
powerhead.

When changing the flow switches, there is a spring on only ONE of them, this MUST be refitted as you dont get a new one with the flow switch kit.

 

[verbis]

Thanks.

So, do I need to replace the flow switch and the dhw switch, retaining the spring and refitting it or do I just need to replace the DHW switch and (retain the spring if that is the switch with it in)?

 

[baxpoti]

The flow switches are the same. Prt No. 240753. The primary flow switch has a spring fitted to it and is on the left. The hot water switch is on the right between the gas valve and pump. They will have blue (or white if original) labels on with the date code ww/yy.

 

[verbis]

Many thanks

I am now on my way to pick up 2 parts and will replace them both. As an FYI in the 11 months since inheriting this boiler I have had to replace the timer, compression tank, one cartridge and now 2 valves. Any recommendations for a new boiler? 3 storey house, 5 beds, 2 baths. No water tank. Boiler in the cellar.

 

[superdupergasman]

Viessman - 333

Vaillant - Ecotech exclusive 838

Worcester Bosch greenstar - highflow 440 or 42kwCDi

They are about the best you will get!