Turbomax 282e diverter valve replace

[Johnking]

Last summer with help here I decided the diverter valve on my boiler needs replacing. An engineer had adjusted the microswitch producing a "cure" but now the symptoms are coming back (intermittent failure to produce hot water). I've obtained a diverter valve and plan to do it myself. I only have some limited plumbing experience, but it doesn't look too challenging according to the service manual. I just wanted to ask if there's anything tricky I need to watch out for on this model?

As I understand it:

Isolate boiler from mains water, gas, electric, shut of CH valves
Drain boiler (NOT rads)
Remove pump
Disconnect everything in given order from diverter
Reconnect new diverter in reverse order
Refit pump
Refill and recommission.

The main thing I don't fully understand is what happens when I open the CH valves prior to refilling. I guess water will drain down into the boiler under pressure. Is there a particular way to do this properly?



Thanks

John

 

[namsag]

No just opening them and repressusing system should have everything working again. When you remove the pump there is 2 o rings that seal it top an bottom clean these and smear these with silicone grease to help them seal again... Make sure the rubber washer from the plate heat ex to divertor doesn`t drop off.... And the litte screw that hold the plate behind the pump can be a pain .Use correct size screwdriver and give it a sharp smack to free it befrore un screwing. Quite an easy job if you strip and replace in a logical manner. Also open hot taps as well as draining boiler

 

[Agile]

Thats not my favourite job!

I allow 1.5 hours and ensure i have a spare hour left in case anything goes wrong like that little screw stuck ot even one of the big pump housing screws seized up.

I also find it VERY tricky without access of 150 mm on the right hand side. Chris says he can do it with no right access though!

Tony

 

[kier]

why not just change the diaphgram assuming that the internal push rod and pivot is working.
can be a trickey job ie fiddly.but i always try a diaphrgam first.i drop botton half of diaphgram cover,take out diaphgram,test by pushing up bearing plate with reasonable finger pressure,if micro switches make,its just the diaphgram.
have i ever changed a diaphgram and charged for a complete valve.answer YES only to people who phone me up and ask for a price to change the valve and people who forget the tea and biscuits.

 

[Johnking]

Thanks for all the tips. I got a whole valve for £50 delivered off an ebay trader (and it seems to be bran new) so I might as well do the whole thing rather than just the diaphragm - someone suggested that other internal parts would also likely be worn anyway. I have no clearance on the RHS, unless I remove a kitchen cupboard from the wall. Sounds like I ought to do just that.

I do wonder if it's just the microswitch - the lever on the DV comes down and presses it, but sometimes nothing else happens. If I press it down then a bit further with a screwdriver it always lights. I might try just swapping the switch from the new part to see if it fixes it.

Thanks again,

John

 

[Agile]

If the switch is not being activated then its virtually always the diverter valve as they wear out after 4-6 years.

Commercially I cannot just change the diaphragm as I would then be likely to be called back if another part started leaking or failed.

I like 150 mm clear on the right and 500 mm underneath!

Tony

 

[kevplumb]

you sure the model no is right

 

[ChrisR]

Push the switch to turn the boiler on, and if the ch flow pipe gets hot yes, you need to change the whole thing.

I still can't see why access is required from the right. Maybe I have some tool like very long pliers which means it isn't necessary...?

Do a search - there are other posts on this.

 

[namsag]

Access from right helps get in an around part but if no access it can still be done quite easily. You seem to have it sussed in your initial post so don`t worry about it. As you have complete valve just change it but in future when it goes again just change the diaphragm at a cost of £5 and will only take 10 minutes longer than changing whole valve. Personally only take half hour to change whole valve but at a cost of £90 would rather change the diaphram and save customers money done 2 last week both in under 40 mins . Sometimes the screws in housing can be tight but a good whack before un doing them soon loosens them....... The only connection i can see you having trouble with is the bottom right hand one which is just a push in and held with a large (usually) black clip. These can be stiff and need a firm wiggle and pull on the valve to free it...As a first time it should not take you much more than an hour.

 

[Johnking]

you sure the model no is right

Yeah, utterly (this time)!

 

[Johnking]

Access from right helps get in an around part but if no access it can still be done quite easily. You seem to have it sussed in your initial post so don`t worry about it. As you have complete valve just change it but in future when it goes again just change the diaphragm at a cost of £5 and will only take 10 minutes longer than changing whole valve. Personally only take half hour to change whole valve but at a cost of £90 would rather change the diaphram and save customers money done 2 last week both in under 40 mins . Sometimes the screws in housing can be tight but a good whack before un doing them soon loosens them....... The only connection i can see you having trouble with is the bottom right hand one which is just a push in and held with a large (usually) black clip. These can be stiff and need a firm wiggle and pull on the valve to free it...As a first time it should not take you much more than an hour.

I think the time taken will be mostly down to me never having done one and wanting to make sure I get it completely right. It is a gas boiler after all.

 

[Johnking]

Push the switch to turn the boiler on, and if the ch flow pipe gets hot yes, you need to change the whole thing.

Do this with the hot tap running?

 

[ChrisR]

Yes.
Hope you've done your Search - you'll see a note about the part which can break

Just doin't be in a hurry. I think the first one I did took me about 2 hours taking my time, but for some daft reason it leaked. I think I had all the bits out again in about 2 minutes...

 

[Johnking]

Yes.
Hope you've done your Search - you'll see a note about the part which can break

Just doin't be in a hurry. I think the first one I did took me about 2 hours taking my time, but for some daft reason it leaked. I think I had all the bits out again in about 2 minutes...

Hmmm....the search suggests either the pump O-rings (got some with my replacement DV) or a small screw that can shear. If you mean the screw, is that a risk when replacing or just when refurbishing the DV?

Also mentioned in search results is the generous application of silicon. What is this magical substance and where does one smear it? On the mating faces of all the unions?

Cheers,

john