MEGAFLOW CENTRAL HEATING Q

[PANYAN]

Hi all

Cental heating has just stopped working on my Megaflow central heating system ,I have still got hot water and their does not seem anything wrong with the boiler But the pump seems to make a funny noise ,took the pump apart and refitted it seems to going but only the first two rads are getting slightly warm and the tank seems full of hot water any help out their before i lash out £180.00 for a new grundfos 25-80 pump.

Q1 DO YOU THINK MY PUMP HAS GONE
Q2 DO YOU THINK ONE OF MY TWO MOTORIZED VALVES HAVE GONE

Thanks for any help.

 

[chrishutt]

£180.00 for a new grundfos 25-80 pump.

That's an unusually large and expensive pump. A 15-50 or 60 is usually sufficient. Is the system exceptionally large?

You don't give any details of the boiler. It might help.

 

[PANYAN]

Hi chrishutt

I believe it is the lagest Megaflow you can get i have a large 5 bed 3 bathroom house and i could not find any one on the internet who stocks a 25-80 pump (whatever that is ).

Thanks

 

[Agile]

I dont know what your beliefs are and they are probably not very relevant !

Sadia make unvented cylinders up to 3000 litres capacity !!!

I hardly think you will have one that size in your house !!!

More likely a 210 or 300 litre ! One tenth of their maximum size!

And if you gave details of your boiler that would enable us to help you better.

Tony

 

[PANYAN]

Hi Tony

Sorry i thought their was only 3 sizes it's the 300 liters that i have and my boiler is a Ideal Classic FF 2100.

 

[Agile]

If the electric immersion heater is switched off and the hot water is still hot then the problem is not going to be your boiler or the pump.

Much more likely to be a motor valve!

One you should be able to trace as controling the hot water as the pipe will go to the cylinder.

The other may have failed or have a faulty control circuit. Depending on the make it may have a metal lever at one end. Push this and "latch" it into the notch to hold it open and you should have heating again! Magic?

Tony

 

[breezer]

25-80 pump (whatever that is ).

it may be one of theses

 

[Agile]

No I dont think its a four headed monster!

Rather a 245 watt single phase pump with a flow rate of 8 m3 per hour and 180 mm centres and 1.25" screwed flanges.

Just a little bigger than usual!

Tony

 

[breezer]

the one in the mddle perhaps?

useless but true:

did you know grundfos make fire pumps (presumably for sprinkler systems, not fire engines)

 

[ChrisR]

Panyan nobody has pointed out that Megaflo is a make of hot water cylinder, which has no relevence whatsoever to your heating.

Put your valve(s) onto their MAN position and your hot water on, and your rads should get warm. This is explained in the reference section.

Do they?

 

[breezer]

Panyan nobody has pointed out that Megaflo is a make of hot water cylinder

but then i am not a plumber or heating engineer

 

[Paul Barker]

If it turns out you do need a pump it's a simple matter of going to a trade counter and asking them to order you one.

I don't think it would be the pump, but I can't tell from what you've said.

Chris has given you the first step in helping us to help you, feedback on that and you'll get more help.

 

[PANYAN]

Hi All

Thanks for your replies I have tried putting the 2 MV's locked in the manual position only had the hot water on but still no heating pump making a slightly loauder noise (not to loaud) pipes and pump and every thing near the tank very hot.

p.s. Just ran out of hot water obviously was not working last night.

Thanks again

 

[ChrisR]

It does sound like the pump's had it then. Check for a build up of sludge between the discs of the impeller, which stops them moving water.

 

[chrishutt]

Also check whether a standard sized (and low priced) pump could be used. What are the pump connections and the distance between them? Typically the connections are 1.5" brass unions. Also what size is the connecting pipework - 22mm, 28mm? It would help if you could post a picture.

Even if a 15-60 pump wasn't strictly up to the peak demand, it would certainly get the system going (providing connections are compatible/adaptable) and would be easily available off the shelf. Should be £50 or so.