Howden Equipment: 7 Questions I Learned the Hard Way (Manuals, Used Gear, and Flushing Radiators)

I’ve handled Howden orders for 8 years and made over $25,000 in preventable mistakes. Here’s what I wish I’d known.

When I started in 2017, I thought I could wing it. Spoiler: I couldn’t. After a $3,200 screw-up with a compressor manual (more on that below), I started keeping a checklist. These are the questions I get asked most — and the ones I wish I’d asked.

1. How do I find the correct Howden screw compressor manual for my unit?

Look on the nameplate for the model and serial number. Then go to Howden’s document portal (you’ll need to register as an equipment owner). But here’s the mistake I made: I downloaded a manual that looked right — similar model number — but it was for a slightly different pressure rating. That cost me $800 in wrong parts. Always double-check the revision date and the specific suffix after the model number. If you’re buying used equipment and the manual is missing, request a copy directly from Howden support with your serial number. They’ll send you the correct one — usually within 48 hours.

2. Is it safe to buy used Howden industrial refrigeration equipment?

Short answer: yes, if you know what to look for. I’ve bought two used ammonia compressors and both ran fine for years. But I only learned after a disaster with a used evaporator that had a cracked tube sheet. The seller said “light use” — turned out it was from a decommissioned plant that ran 24/7 for 15 years. So my rule: Always get a borescope inspection report and a pressure test history. And don’t rely on the seller’s photos. I now pay a third-party inspector about $500 — which feels painful until you avoid a $12,000 repair.

3. What should I check before buying a used Howden tower fan?

Tower fans — like the Howden axial fans used in cooling towers — seem simple, but I got burned on one that had bent blades from improper storage. They vibrated so badly we had to replace the entire rotor. Now my pre-purchase checklist: spin the rotor by hand (feel for resistance or noise), check the blade tip clearance with a feeler gauge (should be uniform within 0.5mm), and ask for a vibration analysis report from the last operation. Oh, and confirm the motor insulation class — a cheap fan might have older insulation that degrades faster in humid environments. (Should mention: I once ignored the clearance check and that mistake delayed a plant startup by 3 days.)

4. How do I properly flush a radiator in a Howden heat exchanger system?

Flushing a radiator — or any heat exchanger core — sounds straightforward, but there’s a sequence that matters. Step one: isolate the system and drain the coolant. Step two: use a flushing agent compatible with your materials (e.g., Howden’s copper-brazed units can’t handle harsh acids). Step three: flush in the opposite direction of normal flow — cross-flow flushing removes more debris. I learned this the hard way: I flushed a bundled-tube radiator forward and just pushed the sludge deeper. That cost me $450 in redo labor and a ruined gasket. Now I always reverse-flush with a pump rated at least 1.5x the normal flow.

5. Can I use a small freezer with Howden refrigeration components?

Absolutely — if you match the compressor capacity properly. A small freezer (like a blast freezer for a lab or a small cold room) often uses a semi-hermetic or scroll compressor, but Howden’s screw compressors can also work for larger small freezers (think 50 kW+). The trap is oversizing: a compressor too big will short-cycle and wear out seals. I’ve seen three premature failures from people who bought a “bargain” used Howden compressor that was 2x the required capacity. Rule of thumb: match the compressor to the evaporator load at your design temperature, not just the freezer volume. Use a simple heat load calculation — you can find free spreadsheets from Howden’s technical library.

6. How urgent is it to get a replacement compressor when one fails?

Very urgent — but not all urgency is equal. I used to think “we can wait a week for the cheap lead time.” Then in March 2024, a compressor failure shut down a cold storage facility. The “cheap” replacement took 12 days. Lost product value? $15,000. The rush delivery option (at $400 extra) would have arrived in 2 days. I now always keep a budget for premium shipping on critical spares. Bottom line: the cost of uncertainty (downtime + lost product) far exceeds the rush fee. We now pre-authorize expedited freight for all Howden compressors because the one time we didn’t, the plant manager threatened to fire me. (Figure of speech — but close.)

7. What’s the biggest mistake people make when ordering Howden parts?

Assuming the part number is correct. I’ve done it myself: I copied a number from an old invoice, ordered five sets of mechanical seals, and they didn’t fit — the compressor had been upgraded three years prior. The old number was superseded. Now I verify every part number against Howden’s current catalog (which is online and updated quarterly). I also call their support line if I have any doubt. That phone call saved me from a $2,500 error last September. Another mistake: not checking lead times before committing to a customer. “In stock” can mean “we’ll make it in 6 weeks.” So always ask for a written delivery date — not just “usually in stock.”

Look, I still make mistakes — but fewer now. If there’s one takeaway: when you’re under a deadline, paying for certainty (certified manuals, third-party inspections, rush delivery) is cheaper than fixing a guess. That’s the lesson I keep re-learning.