Can Grundfos UPS2 fail slowly?

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Hi there,

I have a grundfos ups2 whirring away and it takes ages to warm up the rads in my house, and then only to a lukewarm temperature. When i turn off all the TRVs upstairs to push heat downstairs, the rads down there get hotter, but again they take ages to warm up. The pipes out of 3 way mid-valve are molten hot going to central heating and lukewarm to hot water cylinder, so i know the valve is alright. So the heat is there and heading in the right direction.

Do I need a new pump? or is this a boiler problem? I've desludged our system recently and my in-line filter isnt bringing out much magnetite.

Cheers in advance
 
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Did you remove the pump when you desludged. Sounds like you sent sludge into the impellor of the pump
I took the head off and cleaned out the impeller with a cable tie so should be good. Can I buy a new impeller? Worth a go. Thanks for your reply
 
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Is your system open vented? Have you checked the cold feed/vent connection area with a magnet? Very common for this area to become virtually blocked with solid deposits which can't be removed by flushing. This connection point is usually just behind the pump. If a magnet sticks to the pipe, its because its attracted to the iron oxide deposits. It'll need cutting out and cleaning or replacing.
 
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I took the head off and cleaned out the impeller with a cable tie so should be good. Can I buy a new impeller? Worth a go. Thanks for your reply
If this is your pump what mode/setting is the pump set to?, which one of the green LEDs is illuminated and is it a solid green or a flashing green?

1654207269898.png
 
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Is your system open vented? Have you checked the cold feed/vent connection area with a magnet? Very common for this area to become virtually blocked with solid deposits which can't be removed by flushing. This connection point is usually just behind the pump. If a magnet sticks to the pipe, its because its attracted to the iron oxide deposits. It'll need cutting out and cleaning or replacing.

Yes it is open vented, I'll have to check this out! Thanks
If this is your pump what mode/setting is the pump set to?, which one of the green LEDs is illuminated and is it a solid green or a flashing green?

View attachment 271256
It was solid green on 2, but ive put it on 3 to try and get it round quicker. Putting it on 3 prevents the Vaillant boiler from giving me an F23 error
 
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Is your system open vented? Have you checked the cold feed/vent connection area with a magnet? Very common for this area to become virtually blocked with solid deposits which can't be removed by flushing. This connection point is usually just behind the pump. If a magnet sticks to the pipe, its because its attracted to the iron oxide deposits. It'll need cutting out and cleaning or replacing.
Hi Elkato, here is a pic of my upstairs airing cupboard. Boiler is downstairs. My magnet is sticking on the ubend before the circulating pump and all the way up the pipe before this. Is that a normal place for magnetite build up? I dont understand the direction of travel from the boiler up to here lol. Also is that Fernox TF1 filter in the right place? Cheers for your help
 

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The 22mm and 15mm pipes going upwards are your vent and feed pipes respectively. If a magnet sticks to the pipes in this area, there is a good chance that the pipes are partially or almost completely blocked. I would drain the top part of the system, cut the feed and vent pipes about 6" above the vent connection. Cut pipe below the feed connection and undo the top connection to the filter. You can then remove that whole section. With that arrangement, I'd probably replace with new rather than try to clear it out. You can make the final connections with compression joints in case you need to repeat the process in the future.

While you've got F&E cistern drained take the opportunity to clean it out as it will very likely have a thick layer of gunk in the bottom which you don't want to wash into the system when you refill. Add some inhibitor when refilling.

I'd put this job above the level of standard diyer but should take a plumber no more than a couple of hours. If your confident of your skills its quite a satisfying job to do especially when you cut open the old pipework and see just how bad the blockage is.

Filter probably not in best place but I wouldn't worry about it.
 
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The 22mm and 15mm pipes going upwards are your vent and feed pipes respectively. If a magnet sticks to the pipes in this area, there is a good chance that the pipes are partially or almost completely blocked. I would drain the top part of the system, cut the feed and vent pipes about 6" above the vent connection. Cut pipe below the feed connection and undo the top connection to the filter. You can then remove that whole section. With that arrangement, I'd probably replace with new rather than try to clear it out. You can make the final connections with compression joints in case you need to repeat the process in the future.

While you've got F&E cistern drained take the opportunity to clean it out as it will very likely have a thick layer of gunk in the bottom which you don't want to wash into the system when you refill. Add some inhibitor when refilling.

I'd put this job above the level of standard diyer but should take a plumber no more than a couple of hours. If your confident of your skills its quite a satisfying job to do especially when you cut open the old pipework and see just how bad the blockage is.

Filter probably not in best place but I wouldn't worry about it.
Thanks for your helpful reply. There's also some magnetism down on the ubend before the pump, so I'm going to chop that one as well! Cheers!
 
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Just re-read your post. It may be worth replacing all the way to the bottom pump connection.
 
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Just re-read your post. It may be worth replacing all the way to the bottom pump connection.
That bend at the bottom scares me but I'll give it a go. Annoyingly the magnet is sticking on the first bend after the mag.filter, so carp has got backt there too!
 
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You'll find the bit causing the obstruction will be around the feed vent connection. it'll just be a thin coating to the inside of the pipe as you get further away. If you replace the section between the filter and the pump you should be ok.
That bend at the bottom scares me
Try cutting the pipe just below the feed connection and see how restricted the pipe is. If its bad, cut another few inches and so on. Don't be tempted to scrape the gunk off the inside of pipes that aren't being replaced as it'll likely end up loose in the system to get stuck in the pump later on.
 
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The VCP (vent, cold feed, pump) system above, is IMO, not near as good as the combined vent and cold feed because despite having the vent & cold feed within the recommended 150mm of each other these systems suffer pump over and air ingress even if this only occurs while the circ pump is starting and stopping, this causes corrosion and is why the pipework gets obstructed and you see the gunk in the bottom of the F&E. I have the combined set up from new, 50 years ago, I replaced the original metal F&E tank after 30 years when relocating it to convert the attic into a bedroom, the 30 year old tank was spotless and some of my rads are > 40 years old. I know of several cases where converting to this system cured problems causing constant venting of rads due to pump over/air ingress etc.

You can also install it (no vent) like the other attachment if no isol valve on the cold feed but cold feed must then be 22mm.
 

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You'll find the bit causing the obstruction will be around the feed vent connection. it'll just be a thin coating to the inside of the pipe as you get further away. If you replace the section between the filter and the pump you should be ok.

Try cutting the pipe just below the feed connection and see how restricted the pipe is. If its bad, cut another few inches and so on. Don't be tempted to scrape the gunk off the inside of pipes that aren't being replaced as it'll likely end up loose in the system to get stuck in the pump later on.
So you were absolutely right, completely choked up at the cold feed and vent area. I've now cleared it and replaced some pipe. The system is now getting nicely hot everywhere. I took the pump head off for a clean as well, and it was free of magnetite. When I put it all back on the pump was silent so I gave it a few whacks with a hammer.... I needn't have done that, it was working absolutely fine I just wasn't used to it being so quiet!!

So I'm having major issues now with vent pipe and cold feed getting red hot from overpumping. I'm guessing the F+E tank is acting like a radiator. I assume this is also why it's got all corroded in these pipes in the first place! Pump speed is set to 2, if I go to pump speed 1 then the water only gets to 67degrees. Any idea what I can do to sort it? Thank you so much
 

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