myson midas combi

[peter the plumber]

hi just after some help if possible.Was called to this job today with no hot water.The boiler looks like something from the dark ages.I tried heating that is fine but no hot water, the pump for the dhw does not run.There are two pumps heating one runs fine.Could any one give any help on this one for me as i have never come across one of these.Many thanks peter

 

[namsag]

Not the answer your after pete but, walk away these boilers are more trouble than they are worth touch one bit another bit will leak.Where a pile of shi#e new and get worse with age

 

[peter the plumber]

I think thats what has happened every time they have had a eng out.The boilet has not been touched for18 years not even a service.The owners could not understand why the boiler was faulty they kept sying things dont last as they used to do these have some kind of flow switch that turns on dhw thanks peter

 

[gas4you]

Have you checked for 230v at dhw pump when hot tap running? if so then pump knackered, but as others say avoid like plague and suggest a new combi. 18 years old, i think its past its best anyway

 

[baxpoti]

Have you checked for 230v at dhw pump when hot tap running? if so then pump knackered, but as others say avoid like plague and suggest a new combi. 18 years old, i think its past its best anyway

The other thing to check is the dhw sensor, it was the most common failure that I remember

 

[Agile]

But be aware that the sensor resistance is way higher than you normally expect!!! About 90K cold or higher.

If you take a little time to look at it then its a very simple boiler and really quite a good design.

They are getting towards being 20 years old now and rather due for a replacement but they are still quite repairable if they are not leaking much.

There are fanned versions but most I have seen are natural draught. I doubt that many boiler specific parts are available any more but only the pumps and very rarely the sensors tend to fail.

Tony

 

[peter the plumber]

thanks for your help

 

[pannierstan]

Its got two sensors I thought one on the inlet and one in the outlet to the calorifier.
My stab is the pumps stuffed. If its a Myson unit 5 its been there as long as the boiler.
Great boilers apart from the SFI which was a real bitch. Who the hell designed that airflow sensor

P.S only joking about the great bit but come on they wernt that bad. At least they were made of metal!

Stan