No DHW or Central Heating..Please help

[aggi]

Hello All,

Have been in our house now for 2 years and never had our system work properly. The DHW takes at least 8 hours to heat enough water to have a bath and the radiators have never worked. Occasionally one may come on for a few days and then stop working again.

I decided to give it a go with a mains water flush as described on this forum and all was well. Lots of crud etc flushed away. After the system still was the same so probably didn't do a good enough job.

A day later, however, I now have no heating or hot water.

The boiler fires up for about a minute and then goes off. The flow and return pipes from it remain cold. After a while it fires up again and the pipes remain the same.

Have bled the system and there appears to be no air in it.

Is it possible that whatever may have been an original blockage has moved elsewhere and now stops any flow through the boiler (or has knackered the pump)? Have removed the bleed screw of the front of the pump and tried to turn whats underneath but access is very cramped so not sure if I was successful.

Have a spare pump so is it worth swapping it out or is it just likely to break that one as well.

Would really apreciate any advice to help.

Many Thanks

Aggi

 

[seco services]

is the pump running when the boiler fires up.

abit more info on the system would help more.
boiler make/model.
y, s plan system etc.
do all the rads bleed ok ?
is the f/e tank got water in ?

 

[aggi]

My apologies...

Yes the pump does run (makes a noise and vibrates) when the boiler comes on and indeed when it goes off.
The boiler is a potterton profile 50e
I believe its a y plan with f/e tank above boiler which has water in it.
The rads do all bleed fine.
It also has a drayton Ma1 mid port valve.
A cylinder stat on the cylinder (turned up) and a stat downstairs in a cupboard( seems odd but also turned up high).

Thanks for the speedy response

Aggi

 

[seco services]

what the boiler stat set to ?
tried the pump on the highest setting ?
whats the stat in the cupboard ?

have you opened all the valves etc that you may of shut ?
could be an airlock or badly sludged up

 

[kevplumb]

I believe its a y plan with f/e tank above boiler which has water in it.

and a $ says you didn't lock it mid position when you refilled

is there any vent points near the cylinder View media item 11360

 

[aggi]

The stat is set to 4..when the boiler cuts out if I turn it up to 5 it re-ignites.
Have tried the pump on all 3 settings.
All the valves are as they were before.

I put a magnet (read something on this forum) over the pipework and it is attracted to a bend just after the zone valve on the central heating side. Also to a vertical run on the return about a metre from the boiler.

Is it worth removing the pump and or zone valve to see if they work properly or can I test them in situ?

Cheers

 

[seco services]

I put a magnet (read something on this forum) over the pipework and it is attracted to a bend just after the zone valve on the central heating side. Also to a vertical run on the return about a metre from the boiler.

could be why you have little or no circulation.

Is it worth removing the pump and or zone valve to see if they work properly or can I test them in situ?

useally can tell with out removing them.
remove the pump centre screw and run the system you'll see the spindle turning.
the MA1 has a indicator to tell you what position the valve is in.

 

[aggi]

Hi kevplumb

You're right I didn't lock it when I refilled it. There is a bleed just after it before the cylinder and another on the return before the boiler and both have water. During the summer I noticed that a rad came on even though it shouldn't have so believe it may have stuck open

Thanks

Aggi

 

[aggi]

Thanks seco will check the pump when I get home later

 

[aggi]

Morning,
Well I have checked the pump and the spindle does turn.
Having re read the FAQ on mains flushing I thing my error may have been one of laziness. I used the radiator in the bathroom as a point for the hose to connect and discharge from. I guess it may have just moved all the sludge closer to the boiler.
I think I'll have to put a couple of T's and some isolating valves nearer the boiler and try again.

Unless you can think of anything else. Thanks again for the help so far and will write again when I have more to report.

 

[aggi]

Hello again...

Well last night I cut out a secton of pipe near the boiler so I could set it up for a mains flush and found the pipe to be mostly blocked. Only about 6mm of the pipe is available with the rest scaled up.

View media item 26756
This was on the flow from the boiler where it has a 90deg bend around some other pipes.

I guess I would like to know if the only solution is a powerflush or would that not even solve the problem. Is it likely to only be near the boiler or more likely to be through the whole system. The pipe after the bend is fine so would it be wise to strip back any areas that are attracted by a magnet and replace them or is that just pointless as the bend that's just out of sight somewhere will be just as bad.

If a powerflush is the only option are they all created equally?
Can anyone reccommend someone in the Leigh (Southend on Sea) area.

Thanks again

Aggi