Myson Economist Expert ????

[Hudson]

I own a lovely little white Myson Economist WM30/40BF Boiler. It is approx 18 years old and has served me well for all these years.

A recent problem has been that the boiler pilot light sometimes just goes out..... This started happening about a year ago, and at that time we were having great difficulty in re-lighting the pilot. But after my plumber pal replaced the thermocouple we thought it would work.... it did not (immediately), but after he managed to get to the limit thermostat and turn it, the problem seemed to go.... until now.

It has started to go out again, could it be the thermocouple ? But saying that it is only a year old. Does anybody have any other ideas ? Overall this is a good boiler and i would like to keep it, i will be ringing baxi/potterton tomorrow to see what spare parts availability there are for this model. Cheers.

 

[BOB.DOLE]

sounds like the gas valve needs replacing

 

[Hudson]

A very interesting answer as this was mentioned a year ago when i first had the problem but it seemed to ''go away'' when we replaced the thermocouple and ''messed'' with the limit thermo..... i will check i can still get them from baxi... cheers.

 

[Agile]

If there is a limit stat in series with the thermocouple then I would be checking this.

Its easy for a competent person to do.

As there are safety devices they should only be worked on by a CORGI registered person.

Tony

 

[BOB.DOLE]

A very interesting answer as this was mentioned a year ago when i first had the problem but it seemed to ''go away'' when we replaced the thermocouple and ''messed'' with the limit thermo..... i will check i can still get them from baxi... cheers.

to be honest this is a very simple set up for a pilot lit assembly and if pilot keeps going out 9 times out of 10 its the tc or the gas valve if i where you i would try another tc and dont over tighten it

is the flame on the tc correct

 

[doitall]

Now I would get the corgy guy to check the pilot jet and flame picture, and adjust the pilot flame up a tad.

Whats the Gc number.

 

[doitall]

The GC number is 41-838-82, and the boiler has known problems with the plot, which was modified in 1990.

Things to check.

Pump overrun.
Pilot flame set to 9-12mm.
Pilot adjusment screw is open.
Pilot tube is tight.
Pilot injector is not partialy blocked.
Has the limit stat cut-out.
Does the limit stat have voltage drop exceeding 10mV.
is the thermocouple output measured at the gas control valve 6-10 mV closed circuit.
Does the pilot stay alight.
Replace gas valve.

 

[Hudson]

Wow 'doitall', you are a Myson expert

Cheers for all that, i would never look at it myself, i will get my neighbour (if he will) to have a look, he is a Corgi registered plumber but his main ''job'' is not really 100% central heating so i may well try and get a dedicated ch engineer. I will print what you have mentioned and get it all checked. Thanks for this.

I did check with Baxi and i can still get the gas valve but i am concerned that certain items are now not available (like the burner), and if any of these went then i am up the swanny.

 

[fitz1]

also check for flame lift and wind blowing it out

 

[doitall]

Wow 'doitall', you are a Myson expert

You wish, some of the others know different

I coppied that from the manual

 

[Hudson]

Well cheers anyway.... does this manual happen to tell you what the upgrade was to the pilot in or around 1990 ?

 

[ChrisR]

SHouldn't think so, they aren't keen to imply there was anything "wrong" with the previous ones!

Selected Product: 450491
Description THORN 1441794 PILOT BURNER
151701 ECONOMIST WM15/30BF,WM15/30BFA,WM30/40BF,WM40/50BF,
HOUSEWARMER 45E LEGEND,55 ELECTRONIC 68202109
Retail Price
(Excluding VAT and quantity discounts) £13.362

Selected Product: 446859
Description POTT 68201410 THERMOSTAT LIMIT
1512622 ECONOMIST WM15/30BF,WM30/40BF,WM40/50BF,WM50/60BF,
WM60/80BF,WM80/100BF 386553
Retail Price
(Excluding VAT and quantity discounts) £45.088

New pilot burner and thermocouple will probably fix it. Yes t/c's DO fail in a year sometomes.

Easy to mess up pilots, leave leaks or other problems if you aren't used to them - corgiwallah time.

 

[doitall]

The pilot injector was changed, in addition the burner pressure was revised, and the Ranco C77 type thermostat was used, later models had a new way of connecting the pump over-run stat

 

[Hudson]

This post and it's information has been very helful, thanks for the advice. I will contact a few dealers and see if i can get the parts or if they have been discontinued.

 

[croydoncorgi]

At some point you have to ask yourself: is this a boiler or scrap steel?
Puting money into an 18 year old boiler is usually not a good investment.....