Wilo Gold 50 Replacement Pump

[TCCalvin]

Hi,

I think my pump has died. When hot water is called for, the boiler fires up and I hear a slight banging in the pipes and the pump no longer seems to power up.

I've tried giving it a slight tap with a hammer but this made no difference.

I'm assuming the pump has failed (it's around 22 years old) - would anyone be able to reccomend a suitable replacement (I understand the 130mm measurement and I assume the fitting is 1 1/2")

 

[Johntheo5]

Hi,

I think my pump has died. When hot water is called for, the boiler fires up and I hear a slight banging in the pipes and the pump no longer seems to power up.

I've tried giving it a slight tap with a hammer but this made no difference.

I'm assuming the pump has failed (it's around 22 years old) - would anyone be able to reccomend a suitable replacement (I understand the 130mm measurement and I assume the fitting is 1 1/2")

View attachment 377023View attachment 377024

A 6M Wilo Yonos Pico should make a excellent replacement, I've had one installed for over 6 years and yes the fitting is 130mm X 1 1/2".

 

[TCCalvin]

Thanks for the reccomendarion. Just ordered form Screwfix and will give it a try over the weekend.

 

[Johntheo5]

Make a note of the Gold's speed setting before dumping it, the Pico has the traditional 3 fixed speed settings, C1,2.1M, C2, 3.8M & C3, 6.0M + almost infinite settings, (in 0.1M steps), in CP (constant pressure) & PP (proportional pressure) modes, it also displays the flowrate in m3/hr and the pump power in watts. C2 is probably a good starting point, I have 10 rads, 8 with TRVs and I run the pump in PP mode at 4.6M which gives the required flowrate of ~ 15LPM at 3.6M when all the TRVs are fully open, the power will then fall from ~ 22watts to ~16watts as the TRV's theottle down, my model doesn't display the flowrate.

 

[TCCalvin]

Thanks for the heads up on the settings - I haven't had chance to fit it today but going to give it a go tomorrow.

The old pump is set to 2, I'll start there like you said. Is there much benefit to tweaking it? (14 rads but a lot of them remain off for most of the year due to using Honeywell Evohome and those rooms being unused)

 

[Johntheo5]

Gas or oil fired boiler?.
Have you got a external ABV (automatic bypass valve), check its indexed setting.
Setting 2 on the 5M Gold was probably lower than C2 on the Wilo which varies between 3.8M at zero flow and 3.0M at 1.8m3/hr, 30LPM, but C1 is probably a bit low at ~ 2.0M, you can allways try it on a CP setting, say 2.5M to 2.8M or anywhere you want with this very versatile pump. The supplied info with these pumps is pretty basic but you can see all the pump curves on the link if you have the time/inclination to read it.
The CP (control) settings are (in the houses) to the right of C3 of the CC settings, the required head will flash for a few seconds after each change and then show the flow&power, (the PP settings are to the left of C1).

https://wilo.com/ie/en/Products-and-expertise/en/products-expertise/wilo-yonos-pico/yonos-pico-25-1-6

 

[TCCalvin]

Gas fired boiler, no sign of an ABV?

Cheers for the link too.

 

[Johntheo5]

Are you up and running yet?., if/when so, post a few readings.

 

[TCCalvin]

Had to abort it unfortunatley, the gate isolation valves were still passing water when fully closed.

I've got an F&E tank in the loft so I'm considering trying to bung that and cap the vent pipe to see if it works, whilst keeping the isolation valves "closed" as much as they do close. I've got a wet vac to drain what does come through initially.

I'm unsure whether I need to do anything else as I have hot water from the immersion.

 

[Johntheo5]

That should help, also open shut the gate valves a good few times, might help to make them seal a bit better, if you intend to reuse the old pump isolation valves ensure they have been slackened off the pump ends ready for removal and have two rubber gaskets which should have been supplied with the pump ready to pop in.
The HW cylinder should have no effect as the heating coil is supplied from the F&E cistern.

 

[TCCalvin]

Thanks again for the info. I opened and closed them 2-3 times. Ill try a few more times (I was concerned about damaging them and ending up with a disaster lol).

I wasn't sure if I needed to close any of the other valves in the airing cupboard, there are 4 higher up and 1 at the base of the hot water tank.

Ive been putting off changing a hot water tap that I:m considering changing at the same time as the pump whilst the the F&E tank was bunged.ut wasn't sure if that would be impacted.

Pics attached inside the airing cupboard.

 

[Johntheo5]

When the valve(s) are fully closed, just slacken back say 3.4 turn and nip up again without "horsing" it, doing this numerous times helps to reseat the valve wedge, (except the valves are of crap quality).

Just change out your pump and do the HW tap later as this water supply has nothing to do with the F&E cistern water, if the HW cylinder is gravity fed (as distinct from a UVC, unvented cylinder) then there will be another, much bigger cistern long side the F&E, its called the CWSC (cold water storage cistern) ans will generally supply water to your cold bathroom taps and the toilet cistern, it will also supply the cold water to your HW cylinder, it generally (but not allways) has two outlets, one to the bathroom, the other to the HW cylinder, the isolating valve for the HW cylinder might be behind or to the side of the cylinder, and enters the cylinder near the bottom, close this and open the HW (and any lower) HW tap), when the HW stops flowing, replace the HW tap, you don't have to drain down the HW cylinder.

 

[TCCalvin]

That's great, thanks, I owe you a drink for all of the help.

I've ordered some bungs which should be here today, I'll probably give it a go tomorow and I'll try opening/closing the valves a few times as per your instructions.

 

[TCCalvin]

Pump is in, bung worked perfectly thanks. Just going to have a read of altl the settings before powering up properly.

 

[Johntheo5]

Here are a few readings from mine taken years ago, there is no flow indication but I derived them from the pump curves.