Heatrae Sadia Megaflow 145DD - tripping out

[CBAnglo]

I have the above hot water system in my flat and the thermostat keeps tripping out so we have no hot water.

You can reset it but now the re-set button has broken.

I called a specialist company dealing with electric hot water systems and they have advised that I need a new boiler and are quoting £2,000 for a new 210 tank which has a separate pressure unit?

Firstly, is this a common problem with these kinds of tanks?

Secondly, does anyone know the name of the tank they have suggested - I think £2,000 is a bit steep but never needed to replace a hot water tank before (and I asked for more capacity).

thanks

 

[muggles]

Could be a short circuit or an overheat...you may just need a new immersion heater, get that checked first

 

[gas4you]

I would doubt very much you need a new HW cylinder

Have the immersion stat checked by a sparky.

 

[mickyg]

I don't normally go into London, but I'll make an exception for 1900

 

[CBAnglo]

Thank you for your replies.

Water has now started seeping out of the pressure pipes - is it really worth getting the tank checked for the immersion stat and the pressure cylinder (as I understand this is part of the tank) or should I just get a new tank?

Would rather avoid having to shell out £2k if I can!

 

[gavinda]

definitely get a second opinion. i really would think its just the immersion stat. maybe the whole immersion at worst.

 

[GPlumb]

Get someone to who is qualified to test it/service it. It should be serviced yearly to make sure the safety features are working ok.

You could get 2 new heaters fitted for a lot less than £2000.

 

[CrazyDan]

i had this problem with a heatrae sadia. different model, but its probably the same problem. there was some leakage from different parts, but a qualified friend (plumber) said it was the water pressure being mucked about by a broken thermostat.

apparently the thermostats in these things wear out in only a few years, especially if you live in a hard water area.

my landlord got replacement thermostats for £35 each online, replaced them quick and easy (literally just disconnecting two wires and connecting them to the new ones), and there hasnt been a problem since.

try the thermostats first before you go paying a fortune for something you might not need.

hope this helps,

 

[gas4you]

The hotter the water in the cylinder gets, the higher the pressure is.

Sounds like it is weeping from the TPRV, which is normal in these instances, the safety valve is starting to do its job.

The worst case scenario I could envisage sitting here would be to have 2 new immersion heaters fitted, probably around £150 if anything like the megaflo ones.

 

[Agile]

This is a Magaflow Dave!

I would guess that this is an electric only system with perhaps an on-peak and an off-peak immersion.

Usually tripping is as a result of burned element connections causing overheating. It can also be due to a badly scaled up element. These can sometimes be cleaned up but generally I would recommend replacing the elements after five+ years. New elements inc. stats probably abotu £60 each.

These unvented cylinders should be serviced anually. I would expect that these leaks can be fixed without needing a new cylinder but then we have not seen it!

Cylinders cost about £500-£900 if a Megaflow brand and as a same model swap perhaps aboult £200-£300.

I think Dave has quoted the cost of the parts as being £150. These are a pain to drain! We would charge about £120 plus the cost of each element that comes to about £270!

Tony

 

[gas4you]

This is a Magaflow Dave!

been a long week and working this weekend as well

I think Dave has quoted the cost of the parts as being £150. These are a pain to drain! We would charge about £120 plus the cost of each element that comes to about £270!

Yes, you're correct again

 

[Agile]

This is a Magaflow Dave!

been a long week and working this weekend as well

I thought you normally worked 7 days a week?

I also made a mistake as I was in a hurry to rush out to a boiler repair and managed to combine the names Megaflow ( which is what this topic is all about ) with Magnaclean ® which is a magnetic filter! Neither Chris nor Potty would be very pleased at that!

Tony

 

[gas4you]

I have been of late, especially for the last 6 months, but usually try to have Sundays off, or at least Sunday afternoon off.

Next week looks like being a s*d as well already. Tomorrow booked till 20:30 already, with the final 2 calls 30 miles away

Still, I like to think that putting myself out for the customer is what keeps me busy

They certainly have to pay for the privilege, or rather their convenience

 

[CBAnglo]

Thanks everyone - you have all been very helpful.

Gas4u- you described the problem perfectly. I am afraid I have never had this tank serviced once in the last 3 years and as I am on the Thames, does that mean I am in a hard water area.

It has 145 litres which should be sufficient for 3 people without having to upgrade the cylinder?

It has 2 switches - the economy 7 one has never properly worked (the light goes on but no hot water?) so we use the 24/7 on.

the little controller thing (I am being very technical!) on the 24/7 thermostat was swapped with the economy 7 one when the 24/7 thermostat failed to heat the water. This has given us some hot water but really only enough for 1 person.

Does this sound more like a thermostat problem now?

 

[gas4you]

Certainly sounding that way.

You only get enough HW for one person, because the 24/7 immersion only heats the top part of the cylinder.