Lifecycle of any D5 pump can be significantly shortened if:


- it is used on very low RPM with average to high restrictive loop, having resulting flow rate low;
- it is used with not compatible top or top/res combo, e.g. "chinese" top/res created for barrow/bykski D5 pump clones. Even if those top/res are compatible at mounting point with "original" D5's, correct gaps spacing inside a working chamber are not guaranteed;
- use of matte coolants that are full of powder colorant, which is likely to subside on loop elements including pump's working chamber and impeller, or simply a dirty loop that result in a very low flow (see first point);

Outside of mentioned conditions, any D5 pump including D5 NEXT, should be very reliable and work for decades.

Zitat von »Destruct0Dan«

So just within the last 15 mins I started getting a grinding sound from my PC. Every modders worst fear when we aren't working on a PC. Checked all my fans, nothing. Nothing rubbing against any fans. Put my hand on my tube res/pump combo and it's vibrating really hard.

*EDIT* This was just purchased back mid May of 2020.

Aquacomputer is very good about supporting their gear, but you may have to disassemble the faulty equipment to determine the cause.
If you see something that isn't right, shoot them an email at support@aqua-computer.de.

In most cases the pumps simply have been mounted in wrong direction or there was air in the pump bearing. In this cases the bearing gets hot due operation and the graphite bearing will mold deeper in the plastic of the rotor. When it has sunk deep enough the rotor will scratch at the housing and the pump will of course stop running. Laing is not offering spare parts for the rotor, so we can only offer a new pump motor assembly in this case without the controller unit.

You should check your pump orientation and remove any air from the system.

Nano particles can also grind the bearing but that's not happening so fast.

I've seen reports of D5's running for a decade being oriented wrong. I think an orientation alone is not the whole problem, the main problem is that D5 pumps are coolant-lubricated and if orientation is wrong, it is harder to get air outside the impeller's basement. Though it may not be a trouble if there is more then one pump in a loop.

I bet 99% of D5 faults like OP's are due to three basic conditions I described.
Many people when bulding their loops ignore anti-vibration efforts to their pumps. This is often forcing them to run their pumps at very low rpm (power),resulting not only in a low flow rate but also that impeller not levitating high enough over its ceramic ball bearing.

At the wrong orientation the bearing can run dry. We have seen many pumps with defects due this problem. As long the graphite bearing is surrounded by water it will not heat up. The issue due melted or deformed plastic is mostly the reason at our RMA cases with bearing issues at the D5.

Low rpm will not reduce the lifetime of this bearing. The levitation of the rotor is very small against the magnetic force of this type of motor design. Xylem has much data about it and also the standard pumps are running at the samle "low" rpm in hot heating water. Watercooling loops with clear water glycole mixtures are a great fluid for these pumps and they will nearly last forever. But a dry running bearing is a big problem. Anybody needs to understand that also a running D5 pump with high flow at the loop can be destroyed this way if there is a air bubble in the bearing area.

Then, what conditions you recommend to meet, to ensure there is no air bubble under the impeller?
Are there any, besides not to run pump dry and keep it in recommended orientations (rotor facing up or side, but not downwards)?
D5's impeller (rotor) has thin openings at the center of the bearing, which should help air to escape from under the rotor, if pump is oriented right.

It's easy: Use the pump in the right orientation and use collant without particles. If you hear air inside pump you need to stop / run the pumpe as often as needed to remove it. The air can not leave this are as the centrifugal force of the water is 1000 times higher. So it can only escape if the pump is off.