Dragon boiler issue

[Chippy]

Anyone on here got same control panel as me? My dragon D20 is struggling to keep houses warm because water going into the houses is less than 60 degrees where as it used to be 70 all the time. Trying to decide if I have a faulty sensor etc on the boiler or buffer tank that’s making it cut out before buffer gets to 70. As you can see fan is stopped and flue isn’t that hot but buffer only 64 and by time this reaches houses it’s under 60. Any ideas?

 

[Still Farming]

Have you changed fuel?
Any faulty temp probes?
Are pumps all ok?
Any fault on fan?

 

[tullah]

We have to clean the fan intake every so often as bungs up with crud
restricting airflo.

 

[Chippy]

Have you changed fuel?
Any faulty temp probes?
Are pumps all ok?
Any fault on fan?

Not changed fuel
Probes seem to be ok unless they can be slightly out maybe if they go faulty?
Pumps are turning so presume there ok. The Wilo Bypass pump has red light that comes on now and again but not sure what that means
Fan is turning flat out when it needs to but not sure it seems as effective as it used to......

 

[f0ster]

you might need to keep an eye on the wilo pump, we have a shed full of faulty ones, mostly the centre rotor splits and jams in the housing, prior to this they usually start to rattle

 

[Adeptandy]

Also had pumps turning but not pumping

 

[Chippy]

I’ve noticed my wilo stratos bypass pump is coming on and off a lot and keeps bringing a red light on and says error 36. What does that mean?

 

[Still Farming]

Are Grunphos pumps better track record?

 

[Doing it for the kids]

Are Grunphos pumps better track record?

mostly but they have got fancy. Sometimes you just need a pump to turn on and off, not sense (wrongly) the next lunar moon and adjust accordingly!

 

[f0ster]

you pay slightly more for a grundfos but they last a lot longer, we find that the centre rotor on wilo splits open allowing water to corrode the permanent magnets that then swell and jam in the rotor housing.

 

[Doing it for the kids]

not a fan of wilo either.

grundfos have v good back up too

 

[rollestonpark]

German engineering for you! Not as good as people make out.
Fairly sure grundfos and wilo are the same company (like sister companies). I could be wrong...
But I have had lots of problems with both wilo and groundfos pumps over the years, they're all cr@p, expensive cr@p.
Shop around when you need to replace, as the markup on these is MASSIVE with a big M.

But make sure your heat network isn't full of particles, has plenty of inhibitor etc, fit filters if possible.
Rust and rubbish can be a factor with these pumps, but they are bad pumps in my view.
Also ensure the pump is sized correctly when you replace, a big pump running steady may well last a lot longer.
Athough even more expensive.... twin head pumps (where it's mission critical) could be an option. These pumps take it in turns, 1 runs for a day, while the other has a break, then switches over.
If either breaks, a warning comes up that it needs to be repaired, but carries on running on the good pump. Gives you time to organise a fix.

 

[Adeptandy]

Put the pump on the return and it will double its lifespan provided the position is correct on open vent, not critical on closed system.

 

[rollestonpark]

Put the pump on the return and it will double its lifespan provided the position is correct on open vent, not critical on closed system.

And maybe a filter just before the pump?
I do wonder if the pumps are on the return side, then the water temp will be 10c or more lower, whether this might help the lifespan?
Not sure on that one...

 

[Doing it for the kids]

Put the pump on the return and it will double its lifespan provided the position is correct on open vent, not critical on closed system.

how come?

 

[Still Farming]

Maybe tandem pumps and only 1 running?
Often no inhibitors as heat meters not calibrated for its use ?

 

[Adeptandy]

10-20 Degrees C cooler is the only explanation I can come up with, but the systems with the least trouble with pumps are all on the return

 

[f0ster]

the thing that kills most pumps is metal filings going around the system, pumps have boiler water surrounding the rotor to keep them cool, any filings passing the inlet to the rotor get attracted in and stay there due to the powerful magnets in the rotor, I find the wilo pumps are very susceptible to filings collecting around the rotor which eventually wears through the rotor casing letting water in to the magnets that then swell and jam in the housing, I have a shed full of faulty wilo pumps, mainly the larger ones to fit 32,40,54mm pipes, a magnetic filter in the system just before the pump really does increase its life span, from my experience grundfos appear better able to cope with filings, it is a good idea to strip them down occasionally and clean the rotor if you do not have a mag filter fitted, up to 28mm pipe size mag filters are not expensive but when you need one for pipe sizes above this the price rockets, we make our own now for the larger size of pipe,

 

[Still Farming]

the thing that kills most pumps is metal filings going around the system, pumps have boiler water surrounding the rotor to keep them cool, any filings passing the inlet to the rotor get attracted in and stay there due to the powerful magnets in the rotor, I find the wilo pumps are very susceptible to filings collecting around the rotor which eventually wears through the rotor casing letting water in to the magnets that then swell and jam in the housing, I have a shed full of faulty wilo pumps, mainly the larger ones to fit 32,40,54mm pipes, a magnetic filter in the system just before the pump really does increase its life span, from my experience grundfos appear better able to cope with filings, it is a good idea to strip them down occasionally and clean the rotor if you do not have a mag filter fitted, up to 28mm pipe size mag filters are not expensive but when you need one for pipe sizes above this the price rockets, we make our own now for the larger size of pipe,

Would strong magnets set up on some large 3 inch flow pipes help possibly?

 

[f0ster]

a strong magnet is just what you need but it has to be in the water flow and covered by a plastic sleeve to make cleaning easier, if you examine a domestic mag filter you will find it has a very strong bar magnet covered by a sleeve, the sleeve is removable to allow cleaning, on larger size pipes you need a lever valve either side of the mag filter to allow easy cleaning and then you only need to drain a tiny amount of water, there is usually a lever valve somewhere on the pipe (or there should be) so mount a mag filter just along from this lever valve, you then only need to fit one more lever valve the other side of the mag filter, you will be surprised just how much iron filings are floating around in the system especially if the pipes are carbon steel which they usually are, you also have filings in there from the manufacture of the boiler and buffer etc, I usually fit them on the boiler/buffer return pipe, you find that for the first few weeks they collect quite a lot of filings, they need cleaned weekly at first but then the collection of the filings tails off because it has got the majority of them, while on the subject check the ph level of the boiler water, if it is not what it should be get some more inhibitor in there, if you are on a bore hole get a sample of the water tested in case it is a bit acidic and eating away at the insides of the boiler/buffer, you will never know until it is too late,